Very often, farmers are faced with a problem when it is necessary to buy a forklift, but the purchase can be quite large. If the farm has enough tools, as well as a lot of metal, you can make your own loader for the rear hitch of the tractor.
As an example, you can take the MTZ tractor, since it is one of the most common equipment in the farm, and also has its own hydraulic system and the ability to install attachments from the rear.
Also, despite the fact that a front loader can carry significantly larger loads than a rear-mounted one, it is much more difficult to mount it. For this reason, we will consider precisely mounted loader on the rear canopy of the tractor.
So, what are the advantages of a homemade forklift:
- If the farm has the right tool, or it was supposed to be bought, and there is also the necessary metal that simply lies idle, then you can save a lot;
- You can choose the length and height of the unloading of the future product yourself.
Disadvantages or what problems may arise:
- If there is still no tool and metal, then it would be more expedient to purchase a new or used loader, since self-production may turn out not only to be comparable in cost, but also significantly exceed it;
- Such a loader will be weaker than the factory ones;
There is a possibility of rearing the tractor when overloading the rear part, therefore it is necessary to correctly calculate the boom reach or additionally make the front part heavier.
Necessary materials
A small amount of tools and materials for a homemade loader for the MTZ rear hitch will need a small amount, but the main factor is the ability to handle all the necessary tools.
Tools:
- The main tool will be the welding machine. It is very important to be able to use it, since the strength, reliability and durability of the entire structure, as well as the safety of the tractor driver, will depend on it.
- An accurate metal cutting tool is required. In this case, a grinder, a gas cutter and the like are suitable. The main thing is that the cut is accurate and even.
- Further, you just need a variety of tools that are usually found on all farms: these are adjustable wrenches, and a sledgehammer, and hammers and the like.
Details:
- It is necessary to purchase or remove from unused equipment 3 hydraulic cylinders: one large, which will raise the boom with a bucket and two small ones to change the angle of inclination of the bucket itself. The power of the cylinders is selected depending on how long the boom will be and with what weight you need to work.
- It is necessary to get metal profiles and plates, of which the further structure will consist. Their thickness is also matched to the tasks set for the loader.
- Cylindrical hinge joints are needed, but their selection must be done only after drawing up a drawing of the entire structure. This is necessary not only in order to get the right amount, but also in order to know the load with which they must cope in the future.
- First you need to prepare a drawing of the entire structure, and only then metal cutting, welding and assembly. This is necessary not only in order to use the material as efficiently and economically as possible, but also to better understand the future design and achieve maximum strength. About the construction below.
Step-by-step instruction
Adhering to the instructions, there will be no problems with creating a loader for the MTZ hitch with your own hands:
- First you need to make the frame of the base of a homemade loader for a tractor. It is a rectangle in which the lower part extends beyond the edges, since it must be installed on the rear canopy of the tractor. In the center of this frame there is also a rectangular frame, which is made of two plates and is welded to the top and bottom edges. A large hydraulic cylinder will be attached to this frame at the bottom, and at the top brace, which is attached to the rear and held in stationary the whole frame. There should be four pivot joints on the top face: two in the center for the upper cylinders and two outer ones for the boom. The height of the base is determined according to needs.
- The boom is a prefabricated structure. From the side of the attachment with the base, this is the main and longest part, which represents approximately 70% of the total length. A continuation is attached to it at an angle of 30 degrees, which should look up. Thus, a boomerang-like shape is obtained. You should get two curved profiles, which are connected to each other in three places - at the ends and in the center. Also closer to the central part, but from the base side (approximately 25% of the total length), a frame is welded, to which the second end of the master cylinder is attached.
- The central part of the boom is made in the form of an articulated cylindrical connection, since the bucket control lever is attached to it. It consists of two elbows (bend of 40 degrees), to which two small cylinders are attached on one side, and on the other side a crossbar for further connection directly to the bucket. All the parts described are connected by hinges, and two elbows have one in common.
- Now it's just a bucket. You can either purchase it or make it yourself according to ready-made drawings. You can also use a pallet or bale forklift instead of a bucket.
- If the boom has a reach of more than two meters, it may be necessary to add additional weight to the front. To do this, you will need to weld a basket for sand, concrete blocks or metal loads onto the frame.
Drawing of a lifting frame of a homemade forklift
1 - rack; 2 - hydraulic cylinder for boom lifting; 3 - support; 4 - lifting frame; 5 - bucket tipping hydraulic cylinder; 6 - bucket; 7, 11 - thrust; 8, 10 - bracket; 9 - pointer; 12 and 13 - sleeves high pressure; 14 - bracket; 15, 17 - lever; 16 - retainer; 18 - sidewall.
It is very important to make the central part immediately assembled with a swivel joint, since later it will not work to put it on.
Fixing stand drawing attachments
1 - sidewall; 2, 3, 4 - bracket; 5 - catcher; 6, 10 - lever; 7 - retainer; 8 - stock; 9 - spring; 11 - latch; 12 - axis.
In the video, a homemade tractor loader at work:
Source: http://allspectech.com/stroitelnaya/pogruzchiki-dly-stroitelstva/frontalnye/samodelnyj-na-navesku-traktora-mtz.html
Mounting hoists and cranes for the MTZ tractor hitch
Tractor lifts are one of the types of tractor equipment designed for lifting and moving loads.
Hydraulic manipulator on the MTZ tractor
Hoisting devices mounted on tractor chassis are used in the agricultural industry, construction industry, warehousing and municipal services, when laying pipeline networks and maintaining power lines, as well as in logging.
Types of tractor lifts
Depending on the features of aggregation with the base chassis, tractor lifting equipment is divided into:
- Trailer-type fixed crane devices installed on a cargo platform connected to a tractor with a long drawbar, equipped with a loading boom and a winch with a cable;
- Slewing cranes with a boom located above the tractor chassis or operator's cab;
- Pipe-laying hoists with side loading boom;
- Hydraulic manipulators without a counterweight are boom-type lifts driven by the hydraulics of the base tractor, mounted on attachments of tractors or on semi-trailed or trailed transport and cargo platforms.
Depending on the design of the load boom, hydraulic crane attachments are divided into:
- Attached lifting equipment with a Z-shaped boom, located at the rear of the tractor chassis and located during transportation both along the longitudinal axis of the tractor and across it.
- Mounted lifts with an L-shaped boom, located during transportation along the direction of travel of the tractor behind the base machine or above the operator's cab.
By carrying capacity, tractor manipulators are divided into:
- Devices with a lifting capacity of up to one ton;
- Medium-duty mechanisms designed to work with loads weighing from one to ten tons;
- Equipment for moving goods weighing up to 30 tons.
The design of tractor-mounted lifting devices
The main elements of the tractor lifting equipment installed on the hitch of the base chassis are:
- Cargo boom with various types of lifting devices - hooks, grabs, slings, etc .;
- Working replaceable bodies and mechanisms allowing the use of the lift when performing installation works, leveling and movement of soils and bulk cargo - cradles, buckets, dumps, etc .;
- Devices powered by the hydraulic system of the base chassis that ensure the movement of the load boom in the vertical and horizontal plane, as well as the operation of some models of grippers and other working bodies;
- Device for fastening equipment to the frame of the tractor chassis;
- Safety systems that block the lowering of the boom in case of hydraulic failure.
Lifting equipment aggregated with BELARUS tractors
Highly versatile machines manufactured by MTZ-Holding are aggregated with different models lifting mechanisms from various manufacturers.
Loader crane DEM-151
Designed to work with BELARUS 92P, the four-section manipulator DEM-151 is designed to perform loading and installation work at a height of up to 12 meters, leveling the ground and transporting goods using aggregated trailed cargo platforms.
The high functionality of the complex is provided by a set of replaceable working bodies and a coupling device included in the unit.
Aggregated with a grapple gripper, cargo winch and cargo forks, the machine allows you to lift loads weighing up to 3 tons to a height of 12.1 meters.
A manipulator with a boom angle of 81 degrees can move loads by rotating around its axis 360 degrees.
The set of equipment of the complex includes a cradle DEM-151 UNIC designed for two people with a lifting capacity of 0.2 tons and a lifting height of 12.8 meters.
Hydraulic lifting device MGN-1200
Installed on the rear hitch of BELARUS 82/1221 and 1523 tractors using a three-point linkage scheme lifting device MGN-1200 is used for lifting and moving piece and packaged goods in field conditions and in storage areas.
Equipped with a fixed L-shaped boom with a mechanically adjustable extension, the mechanism is produced in three modifications differing from each other in carrying capacity.
Universal hydraulic lift PNU-10
Aggregated with BELARUS 80 and 82 hydraulic lifting mechanism PNU-10 is used for lifting and moving piece and packed goods and materials.
Equipped with an L-shaped cargo boom with an outreach adjustable in the range from 1.3 to 6.5 meters, the device with dimensions of 1.0x1.7x3.05 meters is designed to work with loads weighing up to one ton.
The Liebherr 944 excavator embodies modern solutions and technical innovations of the manufacturing company. Only industry professionals are involved in product design, and finished models are tested under extreme conditions before being sent to the consumer. Everything technological processes comply with the standards of the engineering industry. Now the company is engaged in the production of modified construction special equipment, which differs from the basic model in the configuration and operating parameters.
Features and Benefits
The advantages of the excavator include the ability to use it in the most difficult working conditions. The performance of the equipment remains invariably high under temperature conditions of -40 / + 65 degrees, which is not characteristic of all the company's products. The ability to work in extreme conditions is the main advantage for Russian consumers.
The manufacturer designed the Liebherr 944 excavator as a special equipment designed for work in a mine or quarry, loading, unloading and transporting materials. At the moment, it can be used for fast and high-quality performance of loading and unloading operations in any industry, for the demolition of construction sites, during the construction of new buildings and structures, as well as for earthworks. Thanks to the installation of a large-volume working body, the duration of working operations is reduced, and the versatility of the machine allows it to be used almost everywhere.
The considerable digging depth and large bucket ensure efficient work, while the track base ensures stability and flotation.
Specifications and dimensions
The main specifications Liebherr 944:
The dimensions of the Liebherr 944 excavator are 11.35 mx 3.2 mx 3.35 m.The length of the undercarriage is 4.92 m, the width of the tracks is 0.6 m, the track is 2.4 m. Ground clearance is 0.54 m, and the tracked base is 4.11 m.
Power apparatus
The equipment is equipped with a motor of our own production with a capacity of 190 kW or 258 hp. The six-cylinder D936L has a 10.5 liter displacement and operates on diesel fuel... The cylinders are installed with a diameter of 122 mm. In terms of exhaust quality, the power plant complies with international Tier 3 and Stage 3A standards. The engine speed is 1800 rpm.
The engine comes standard with a supply air cooling system and a turbocharger. Optional installation is offered particulate filterwhich guarantees efficient cleaning.
Fuel consumption
The Liebherr 944 fuel tank has a volume of 705 liters and an average fuel consumption of 22.3 liters per hour of operation.
Device
Thanks to the use of a strong and reliable design, maximum performance is achieved when performing hard work in extreme conditions. The developers took care of the possibility of completing the machine different kinds chassis and attached working bodies, which ensures the versatility of the Liebherr 944 excavator. The production of components and assembly of equipment is carried out in Germany in accordance with national and international standards. This ensures high quality both individual parts and the product as a whole.
Long boom equipment is installed on the excavator, which makes it possible to carry out work from one parking place. To ensure the stability of the special vehicle on any base, a complete set with a caterpillar base and a rational distribution of the Liebher 944 weight are provided. As standard, an air conditioner is installed on the excavator, which is controlled through an automatic sensor idle move... In addition, the basic assembly includes the installation of a stability enhancement system when working on rocky ground. The reliability of the case is due to the use of heavy plate steel in its manufacture, as well as the application of a durable paintwork. This eliminates the occurrence of corrosion and damage due to mechanical stress.
Due to the high 944, it is possible to perform complex tasks in a short period of time, as well as work with IV category soils. Low base pressure allows the excavator to move and work on unstable ground without losing productivity. The manufacturer positions this product as the most efficient in terms of digging performance.
The construction of special equipment is designed for use in the most difficult working conditions. The main material for its manufacture is high-strength steel, which makes it possible to use the excavator everywhere, regardless of climatic conditions... Its versatility is due to the large number of mounted implements and various types of chassis. The consumer can independently select the necessary elements, thereby ensuring maximum efficiency when performing work operations.
All excavator equipment produced by the German manufacturer Liebherr has a variety of advanced technological solutions and innovative developments, thanks to which this brand can be called one of the leading ones. In the process of product development, for the most part, only professional employees with rather extensive experience are involved, which is precisely what explains the increased quality of the machines. Nowadays, a huge number of various modifications and basic models with similar equipment and differing technical characteristics.
Description and features
One of the models in the excavator line is the Liebherr 944 crawler excavator. It should be noted that compared to others german cars, this model is not so popular in the world market of special equipment. But high demand yet the model is available on russian market, since it has not the largest overall dimensions, which in turn allows working in conditions with a small working space.
This excavator, like most other models, is capable of withstanding very extreme operating conditions. All parts of the machine, systems and units ensure maximum trouble-free operation even at temperatures from minus 40 degrees Celsius to plus 65 degrees Celsius, which makes the equipment especially in demand when working in the northern regions of Russia. Not all similar models can stand out with this indicator, which makes the equipment one of the best in Russian operating conditions.
Thanks to the reinforced construction, the Liebherr 944 crawler excavator is able to cope with increased loads. As additional options installation is provided different types undercarriage platforms and attachments. All this provides an opportunity for the consumer to choose the optimal configuration of the excavator capable of performing certain types of work. The very same serial production of this excavator takes place in Germany at specialized enterprises of the brand, which additionally ensures not only high quality, but also increased reliability, which is simply necessary for such equipment.
The model has an elongated boom, which is much longer in size than the model itself, which became one of the key features. But, it would seem, with such equipment, the technique is most prone to overturning, but the manufacturer solved this problem by means of a well-thought-out design of the tracked platform. Thus, a third of the bucket load is transferred to the tracked chassis, which, together with the rear counterweight, provides excellent stability and allows the excavator to work with fairly heavy loads.
The Liebherr 944 crawler excavator comes standard with a high-performance air conditioner controlled via an automatic idle sensor. In addition, the equipment is equipped with special systemproviding increased stability when operating on uneven surfaces or on rocky soils. The metal used in the design of the model has an increased thickness, which, together with paintwork guarantees reliable protection from corrosive processes.
This model has become one of the best in its class mainly due to unique features, which are more than enough in this model. Also, all this provides equipment with a quick payback, which is especially important in small construction organizations.
A distinctive feature of the entire design of the model is quite low level centralization of gravity, due to which a certain proportion of the mass is transferred to the tracked platform, which allows the equipment to withstand very heavy loads without any problems. It also has a positive effect on the performance of the excavator. Another advantage of the design is the ability to perform any operations with rocks and other materials with increased strength.
The machine stands out for its low sag characteristics when working on uneven surfaces. And at the same time, the excavator provides high quality of work performed, as well as increased productivity. In terms of efficiency in earthmoving, the Liebherr 944 can be called one of the leaders.
It should be noted that the manufacturer developed the design of the equipment specifically for operation with high loads. It is made of high strength steel and ensures the most efficient use of the machine in a wide variety of activities. The high versatility of the excavator is due to the large number of additional attachments and several options for the platform used, which allows the owner to collect from all this the most suitable variation of equipment for doing specific tasks.
It is also necessary to highlight the next element of the model. The excavator is equipped with a modern operator's cab, which includes reliable safety systems (ROPS and FOPS), microclimate systems (air conditioning and heating systems), as well as a high-quality radio receiver. The cab design is characterized by fairly large windows, providing a wide view of the working area. Inside, a comfortable seat with several adjustments and air suspensionwhich eliminates vibration. To achieve an increased level of safety, the cab has been supplemented with special reinforcements, which guarantee reliable protection in the event of an excavator tipping over. Also responsible for safety here is the modern FGPS device, which is included in the standard cab. In addition to the rear-view mirrors, an optional camera can be installed that transmits a clear background image. Thanks to it, an improved view is achieved and possible blind spots of visibility are excluded.
The basic version of the Liebherr 944 is equipped with the Liebherr SW66 quick coupler, which has hydraulic drive and a special mechanism that automatically lubricates the joints of the working equipment. As previously described, the technique can be equipped with many additional units that expand the scope of application. Among these, it is necessary to highlight hydraulic shears, hydraulic breaker, grab buckets, ripper, auger drill, grab and several types of buckets that differ in their capacity. All of the listed equipment is the most popular, but in fact this list contains many more attachments.
This model uses a diesel six-cylinder power unitdeveloped by Liebherr. The engine has an index D936L and is equipped with direct injection, fluid system cooling and turbocharging system, which is paired with a special intercooler, provides quite excellent power performance. So, the unit is capable of developing a rated output power of 190 kilowatts, which translates to 258 horse power... The engine transfers power directly since this excavator model does not have a gearbox. All movement of equipment is carried out only at one speed, namely 5 kilometers per hour. The main feature of the unit is quite good efficiency, which with a spacious fuel tank (705 liters), provides long-term operation without stopping for refueling.
Appointment
The main goal in the development of the Liebherr 944 crawler excavator was the ability to move large mass soil and various materials extracted in mines and quarries. But the numerous features of the technology made it possible to significantly expand the scope of application, since at present the model is used in almost all areas of activity, from construction to large industrial sectors. Everywhere the machine is used for loading and unloading any cargo, dismantling, transshipment operations, all types of earthmoving and much more, depending on installed equipment... But it is worth noting that most of the work performed is carried out using a standard bucket, which has an average capacity. Traditionally used to transport equipment to work sites special transport... And this is not due to the fact that the equipment is moving rather slowly, but also because of the possible damage to the asphalt and concrete pavement of the road sections, which can be inflicted by the caterpillars.
Modifications
This model served as the basis for two modified versions. Let's proceed to their detailed consideration:
Modification of the Liebher 944B. This model features optimized power plant, which made it possible to achieve increased operational and technical parameters... Another significant difference is dimensions excavator in connection with the installation of an extended tracked base. IN standard configuration This model has a larger or smaller digging bucket.
Modification of the Liebherr 944C. Distinctive features such a modification is the presence of a modern hydraulic system with increased operational parameters. The used hydraulics can significantly reduce material costs during maintenance, as well as reduce fuel consumption. The version also outperforms the standard excavator in terms of performance.
A photo
Specifications
Bucket specifications:
- The bucket to be installed is a backhoe.
- The smallest capacity of the bucket to be installed is 1.0 cubic meter.
- The largest capacity of the bucket to be installed is 2.5 cubic meters.
- The maximum digging depth is 8900 millimeters.
- The maximum digging height is 14950 millimeters.
- The maximum bucket dump height is 11100 millimeters.
- The maximum digging radius is 13,300 mm.
- The maximum force on the bucket cylinder is 326 kilonewtons.
Engine characteristics:
- The type of the installed engine is in-line, diesel.
- Engine brand - D936L.
- Engine builder Liebherr.
- The number of cylinders is 6.
- The working volume of all cylinders is 10,500 cubic meters.
- Rated power output - 190 kilowatts / 258 horsepower (at 1800 rpm).
- Rated speed crankshaft - 1800 rpm.
- The diameter of the cylinders is 122 mm.
- The piston stroke is 150 millimeters.
- Cooling system type - liquid.
- Starting system type - electric starter.
- Turbocharging system type - gas turbine with subsequent cooling of the charge air.
- Average fuel consumption per working hour is 22.3 liters.
- The highest speed of independent movement is 5 kilometers per hour.
Dimensions:
- The constructional length of the excavator is 11,400 millimeters.
- The full width of the tracked platform is 3195 millimeters.
- The total height on the roof of the cab is 3350 millimeters.
- The length of the undercarriage is 4915 millimeters.
- Tracked (standard) base - 4108 mm.
- Track (extended) base - 4400 millimeters.
- Track gauge (standard platform) - 2390 mm.
- Track gauge (extended platform) - 2900 mm.
- The length of the rear of the turntable is 3470 millimeters.
Price
The cost of the new model at the moment ranges from 17 million rubles to 18 million Russian rubles. It is worth noting that only modified versions are available, since mass production of the base one was discontinued. Those supported have a price from 7 million rubles to 9 million Russian rubles.
The increased demand for mining hydraulic excavators in recent years is due to a number of important advantages that a hydraulic drive has compared to a cable drive:
The minimum duration of the working cycle;
Increased digging effort;
Wide range of bucket trajectory;
Effective bucket filling, especially in low face heights;
Possibility of more complete extraction of minerals in conditions of selective mining.
Experience in the design, manufacture and operation of hydraulic excavators shows the following:
Excavators have smaller dimensions than cable cars while ensuring the same bottomhole parameters;
Their weight is half that of rope excavators with the same bucket capacity;
High mobility and maneuverability;
The hydraulic drive provides the ability to work on sites with a slope of up to 15 °.
Backhoe hydraulic excavators have the added benefit of digging patterns. The digging depth of backhoe excavators - depending on the type, size and modification - ranges from 4 to 18 meters.
Backhoes are effectively used in waterlogged conditions: for sinking sump, laying channel branches. Backhoes have particular advantages in non-explosive mining of semi-rock.
Liebherr is widely recognized in the world market as one of the leading companies in the production of a wide range of equipment for the mining industry.
Liebherr produces 180-400 hp open-pit dozers. and single-bucket wheel loaders with a bucket with a bucket capacity of up to 5 m3 at factories in Austria, mining dump trucks with a lifting capacity of 150-360 tons at a plant in the USA and 17 types of crawler hydraulic excavators with a working weight from 10 tons to 650 tons at a plant in France.
Liebherr currently offers the consumer 7 basic models of hydraulic mining excavators: R-964 B (working weight 60–67 t), R-974 B (78–83 t), R-984 C (111–116 t), R -994 (226-229 tons), R-994 B (261-265 tons), R-995 (420-432 tons), R-996 (647-653 tons). All models are equipped with working equipment of forward and backward shovels (tables 1 and 2).
Until 2002, a model of the R-992 mining excavator with a working weight of 135-144 tons with a bucket of up to 12 m3 was produced. Since 2002, two excavators of this model with front shovel equipment have been successfully used at the Kayerkansky open-pit of the Norilsk Mining and Metallurgical Company for loading blasted dolomites and non-explosive coal mining.
The designs of modern Liebherr excavators embody the experience gained over several decades of their operation in various mining and geological conditions in open pits around the world.
All models of excavators have special modifications adapted to work at temperatures down to –40 ° С, and new excavators such as R-994B and R-995 - at temperatures down to –50 ° С (arctic version).
Excavators weighing more than 100 tons are equipped with electric drive, with this option, the excavator can be equipped with a cable winder mounted on the machine base.
The design feature of Liebherr excavators is the low center of gravity of the machines due to the mass distribution of powerful working equipment and a heavy undercarriage: more than 40% of the excavator's weight is on the undercarriage.
The increased stability of the machines when working in a heavy rock face, even with an uneven footing, provides an efficient transformation of high penetration and breakout forces of the bucket. Liebherr excavators have the highest digging and breakout forces in their classes in relation to the working mass, that is, they are the most energy equipped. This ensures high performance, reliability and durability of hydraulic excavators.
The developed layout and kinematics of the working equipment of the forward and backward shovels allow full use maximum effort on the bucket teeth along the entire trajectory of its movement, which ensures its filling in the shortest possible time.
The semi-parallelogram geometry of the front shovel working equipment provides a stable penetration force throughout the digging cycle due to the hydraulic cylinders located on the boom, not on the stick. Automation provides simplicity and ease of control of the digging process.
Backhoe kinematics of Liebherr excavators provide high digging and breakout forces, which ensure their efficient operation in the gross excavation of soft, blasted semi-rock and rocks by bottom excavation with loading into vehicles at various locations. Bottom digging and bottom loading ensure maximum productivity due to the minimum swing angle (up to 11 °) for unloading the bucket.
The working equipment of open-pit mining shovels can be manufactured according to the parameters of the specific work performed by the excavator in the open-pit. Therefore, each basic backhoe model has a large selection of extended attachments and matching bucket modifications.
Backhoes from Liebherr are widely used in non-explosive mining of semi-rock. To expand the area of \u200b\u200btheir application in non-explosive excavation, the back shovels are equipped with a special ripper tooth, mounted instead of the bucket.
The Backhoe Ripper was first developed by Liebherr specifically for use in difficult conditions... At the same time, a quick change of the bucket to the ripper and vice versa is provided by the adapter of the original design, which allows changing the working equipment in 15–20 seconds. All Liebherr mining shovels are equipped with these devices with an operating weight of up to 115 tons.
Liebherr is constantly modifying the existing the lineup mining excavators, as well as complements it with new models.
R 964 B Litronic 63 t working weight since 2001 equipped with a six-cylinder V-shaped diesel engine own production with a capacity of 270 kW, which allows an excavator (backhoe) with a bucket of 3.4 m3 to develop a digging force of 279 kN.
The new modification R-974 B Litronic with an operating weight of 84 t is equipped with a 360 kW Liebherr 8-cylinder engine, which fully complies with the European and American standards EG II and TIR II. This significantly reduced fuel consumption and noise levels.
In 2001, an R-995 open-pit excavator with a working weight of 420 tons, equipped with a 1600 kW MTU V16 diesel engine, was put into commercial operation at one of the Spanish open-pit mines. High digging forces - 1150 kN and breakout - 1400 kN are provided by a set of improvements in hydraulic system, machine kinematics and computer system management. The special design of the 23 m3 bucket allows the cycle time to be minimized to 28 sec.
The R-994 B was the latest development of the Liebherr plant in Colmar in 2002, which differs from the long-standing R-994 with an operating weight or more. powerful engine (Tables 2 and 3).
The R-994 B is a classic 15 cc machine with a weight of 265 tons. This state-of-the-art mining excavator is equipped with cummins engine QSK 45 with 1500 hp, which allows to develop digging forces of 1300 kN (front shovel).
As with all Liebherr mining excavator models, the R-994 B uses box-shaped steel structures with steel castings at stress concentration points, which gives the structure special rigidity and provides high resistance to torsion and bending.
In general, the reliability of Liebherr machines is ensured by the design feature and a large proportion of units of its own production, which reaches 90%. Engines, hydraulic pumps, hydraulic motors, hydraulic cylinders, gearboxes, slewing rings, electronic systems management, on-board computers, all metal structures, even air conditioning systems, are components of the company's own production in the development and manufacture of which the standards and technologies adopted in the space and defense industries are used.
