BOILER AND UNIVERSAL DIGGING MACHINES
Questions for control and self-examination
1. What is the principle of operation of a military single-bucket excavator?
2. Report the purpose of EOV-3521 and EOV-4421.
3. Report the general arrangement of EOV-3521 and EOV-4421.
4. What kind of military single-bucket excavators do you know?
5. Report the performance characteristics of EOV-3521 and EOV-4421.
6. What constructive differences between EOV-3521 and EOV-4421 do you know?
Chapter 14
Pit machines are designed to cut excavations for various fortifications. The engineering troops of the Russian Army are armed with two excavation vehicles MDK-2M and MDK-3.
It should be noted that the MDK-2 foundation pit vehicle (1962) is the first special model of a military foundation pit vehicle in world practice. The experience of its operation in the troops made it possible to create a new, more advanced machine MDK-3. The MDK-3 machine is equipped with a cross-digging milling working body with a drum-type thrower and additional working bodies: a ripper and a bulldozer with a skewed blade.
The main tactical and technical characteristics of the foundation pit machines are given in Appendix 10. Analysis of the data in this table shows that the MDK-3 machine is significantly superior in its performance to the MDK-2M machine. Its productivity and transport speed are 2.7 and 1.8 times higher, respectively. The MDK-3 machine can loosen heavy non-frozen and frozen soils, level the sites for work on slopes, which cannot be done with the MDK-2M machine.
To extract the pits to the full depth, the MDK-2M machine needs to make 8-9 passes, while the MDK-3 machine tears off the excavation in one or two passes, therefore, the time loss for idle runs and turns for the MDK-3 machine is significantly less or completely absent. However, the MDK-3 machine is much more complicated in design and operation.
In general, excavation machines have a fairly high performance when cutting excavations. However, they cannot work in frozen ground. One of the disadvantages of the machines is that they cannot produce excavation pits of only one width (3.5 m).
Another disadvantage. The vehicles are poorly protected from bullets and shrapnel, as well as from the damaging factors of weapons of mass destruction. Based on this, it is advisable to use this type of vehicle outside the zone of direct contact with the enemy.
Trench-excavation machines in the Russian Army are represented by the PZM-2 regimental earth-moving machine, which is designed for cutting trenches in frozen and non-frozen soils, and pits for military fortifications - only in non-frozen soils. Also, the machine can perform simple bulldozing work.
The main performance characteristics of the PZM - 2 are given in Appendix 10. Their analysis shows that in a number of properties the vehicle does not fully meet the requirements of the troops. It has a low transport speed, has insufficient traction and coupling properties, and does not have protection against the damaging factors of small arms and weapons of mass destruction.
Universal machines are presented in the RF Armed Forces by single-bucket excavators. They cut trenches, ditches of all sizes, as well as excavations of various configurations. The presence of a hook holder on excavator equipment allows you to independently install some forts, as well as to carry out, if necessary, loading and unloading operations in wartime.
(sixties-seventies)
Machine for cutting pits MDK-2m
The machine for cutting pits MDK-2m is designed for cutting trenches and shelters for equipment, pits for fortifications (dugouts, shelters, fire structures). The dimensions of the pits: width at the bottom 3.5m., Depth up to 3.5m., Length as required. Classes of developed soils I-IV.
Productivity according to the amount of excavated soil is 350 cubic meters. in hour.
When pulling out pits, the excavated soil is laid in one direction to the right of the pit in the form of a parapet. If it is necessary to arrange a parapet on both sides, after two or three passes, it is necessary to change the direction of the passages. In one pass, the deepening is 30-40 cm. The beginning and end of the pit are gentle ramps with a slope of 15 degrees. Bulldozer equipment allows you to use the machine for backfilling pits, devices of gentle slopes. Permissible lateral slope during operation up to 15 degrees, ascent / descent angle during operation up to 28 degrees.
The base vehicle is an AT-T heavy artillery tractor. Engine power 305 hp, weight 27.3 tons, transport speed up to 36 km / h. The cabin is pressurized, equipped with a filter-ventilation unit, due to which the machine can operate on an area contaminated with poisonous and radioactive substances, and the crew (2 people) in the cabin can be without protective equipment. The cab can accommodate up to five people, including the driver. the fuel supply will last for 500 km. run or 10-12 hours of work in the ground. Time to prepare the machine for work 5-7 minutes. There is a place for the installation of the radio station R-113 (tank), but it is not completed. Equipped with a rethngenometer radiometer, a set of PNV-57T (night vision device).
Is in service in the engineer battalion of the motorized rifle (tank) division - 3 pcs.
From the author. The machine is durable, reliable and trouble-free. There is no more productive earth-moving machine in the army. For comparison, the excavator has a capacity of 40 cubic meters per hour. The vehicle tears off a trench for a tank in just 10 minutes, and manual modifications are not required. The cabin is spacious and warm (engine under the cabin floor).
Sources of
1.Instruction on the material part and operation of the machine for excavating pits MDK-2m. Military publishing house of the USSR Ministry of Defense. Moscow 1968
2. Military engineering training. Tutorial. Military publishing house of the USSR Ministry of Defense. Moscow. 1982
Pit excavation machine MDK-2M is intended for excavation of pits for fortifications, for engineering equipment of positions of troops and for mechanization of earthworks during carrying out and their consequences.
Pit machine MDK-2M consists of a base machine (product 409MU) and working equipment.
The working equipment includes: working body, transmission of working body, bulldozer equipment and hydraulic drive (working equipment control system).
Rice. 1. Pit machine MDK-2M:a - side view, b - rear view;
1 - blade, 2 - hydraulic cylinder, 3 - rack, 4 - base machine, 5 - hydraulic tank, 6 - protective shield, 7 - thrower, 8 - upper frame, 9-beam, 10 - lifting frame, 11 - plow, 12 - thrower cover, 13 - milling cutter, 14 - push frame, 15 - protective shield (folding part) 16 - protective shield (fixed part), 17 - slope, 18 - beam, 19 - plow, 20 - adjustable struts, 21 - lifting frame ...
The working body is intended for the development of soil in the process of excavating a pit and transporting it to a dump. It is installed in the rear of the machine and is pivotally attached to it with the ability to move in a vertical plane. The main parts of the working body are the lifting and upper frames, the cutter, the thrower, two plows, the guide cover and the lifting and lowering mechanism.
The lifting and upper frames are designed to fix all major parts of the implement.
Lifting frame is a welded structure of a U-shaped box-section. In the middle transverse part of the frame, the cutter and thrower drive gear is mounted. The ends of the frame longitudinal beams are pivotally connected to the machine body. Two hydraulic cylinders of the mechanism for controlling the position of the working body and two brackets for fixing the working body in the transport position are attached to the lugs on the longitudinal beams.
Upper frame mounted on top of the lifting frame. It is welded from two longitudinal, two vertical and transverse beams. Two slopes and a protective shield are attached to the upper frame.
Slopes are designed for cutting the soil in the upper part of the pit to form a slope of the walls and are a knife with wear-resistant surfacing, which returns to the working position and is fixed manually with the help of two fingers and their drive levers. In the transport position, the slopes return to the axis of the machine.
Protective shield designed to prevent the machine platform from filling with soil when digging a foundation pit. It is installed on the upper frame of the working body and consists of an upper folding and a lower fixed part. In the working position, both parts of the shield are kept in the same plane. When lifting the working body, the folding flap is locked into the transport position by means of a rod and springs.
Milling cutter transverse digging is designed to break up the soil and feed it into the thrower. It consists of a hub and six triangular-section blades welded to it. Three variable cutting blades are bolted to each blade, the cutting edges of which have wear-resistant surfacing. For the purpose of uniform wear, the knives are rearranged in places: the extreme ones themselves, worn out, are installed closer to the hub. The cutter is bolted to the planetary gear hub of the implement gearbox.
Thrower designed for transporting the excavated soil to the dump. It is a fixed guide casing and a bladed drum of a welded structure, which consists of a hub, five box-section spokes, a rim with fifteen blades, of which thirteen are welded to its rings, and two are removable in order to replace worn out sheets of the guide casing without removing the thrower. The thrower hub is mounted on the implement gearbox.
Plows(right and left) cut the soil under the track pads to ensure that the cutter is excavated on subsequent passes of the machine. The left and right plows are similar in design and consist of a body with knives fixed in the lower part, a blade, an axis and a height adjustment mechanism. A thrust plate is installed on the plow axis, connected to the body by four bolts. In case of normal force on the knife, the plow returns to the stop with the plate into the upper frame. When the plow meets an obstacle, the bolts are cut off, protecting the plow from breakage.
Guide shroud ensures the movement of the soil from the cutter to the thrower and then to the dump. It embraces the blades of the cutter and thrower from below and is a frame consisting of two interconnected arcuate beams, between which removable sheets are attached. To increase the rigidity of the casing fastening, two removable beams are installed, each of which is attached with one end to the casing guide, and the other - to the lifting frame.
Lifting and lowering mechanism the working body is designed to change the position of the working body in height. It consists of two hydraulic cylinders, pivotally attached to the machine body and the lifting frame, and provides rotation of the working body when transferring from the transport position to the working position or vice versa, its deepening, lifting and fixing. The angle of rotation is limited upward by the stroke of the hydraulic cylinder rods, downward - by the stop of the lifting frame in the machine body.
Working body transmission MDK-2M
designed to change and transfer torque from the speed reducer to the cutter and thrower. It consists of an intermediate shaft, two cardan shafts, a slewing gearbox and a working body gearbox.
Intermediate shaft is a link between the speed reducer of the base machine and the drive shaft of the slewing gear drive. It is a pipe, to the flange of which a gear rim with an internal tooth is attached to connect the speed reducer to the gear half of the power take-off shaft. On the splines of the other end, a flange is installed for fastening with a propeller shaft fork. The shaft is supported by a spherical bearing.
Cardan shafts one is installed between the intermediate shaft and the slewing gear, and the second is installed between the slewing gear and the reducer of the working body. They are the same in structure, but have different lengths.
Swing gear designed to change and transfer torque from the speed reducer to the working body reducer. It is installed in the aft compartment of the machine body and provides switching on and off, changing the rotational speed of the cutter and thrower, maintaining the alignment of the driven shaft with the drive shaft of the working body gearbox when changing the relative position of the gearboxes. Gear ratios of the gearbox are equal to 1.08 and 0.856.
The main parts of the slewing gear are: housing (stationary part, sleeve, rotary part), drive shaft assembly, first and second intermediate shafts assembled, pinion shaft, control drive and overload clutch.
Working body reducer designed to change the torque that is transmitted to the cutter and thrower. It is mounted on a lifting frame and provides simultaneous rotation of the cutter and thrower at different angular speeds.
The working body gearbox consists of a single-stage spur gearbox and two planetary gear sets made in one unit.
Frame single-stage helical gearbox is attached to the housing of the first planetary gear set. The hatch cover has a hole for filling oil and installing a dipstick. The driven shaft is made in one piece with the sun gear of the first planetary set.
First planetary row designed to change the torque and transfer it from the spur gearbox to the second planetary gear set and simultaneously to the rotation of the thrower. It consists of a housing connected to the housing of the second planetary gear set, an epicyclic gear, four satellites and a carrier, which is simultaneously the sun gear of the second planetary gear set.
Second planetary gear set designed to change and transfer torque to a cutter mounted on bearings on the outer surface of its housing. The carrier has an axial hole through which a torsion shaft passes, which connects the carrier of the first planetary gear set with the thrower rotation flange. At the end of the carrier there is a ring gear for connection to the milling cutter hub. During operation, the torsion shaft acts as a damper, protecting the transmission from damage.
Fig. 2. MDK-2M working body transmission:
1 - intermediate shaft, 2 and 5 - cardan shafts 3 - slewing gear, 4 - safety clutch, 6 - working body reducer, 7 - hydraulic pump reducer, 8 - base machine gearbox, 9 - speed reducer
Bulldozer equipment MDK-2M
intended for layer-by-layer development and movement of soil when planning the bottom of the pit, preparing the site before starting to dig the pit. In addition, with the help of bulldozer equipment, it is possible to backfill pits, trenches, and fluff up frozen soil at a freezing depth of up to 15 cm.
The machine is equipped with dozer equipment with a fixed blade, the height of which is 1000 mm, and the length is 3200 mm. With the help of hydraulic cylinders, the blade can be lowered below the machine's standing level by 540 mm or raised to a height of 1140 mm. Equipment weight is 1120 kg.
The bulldozer equipment consists of a blade, two push frames, two front struts with struts, two ties and a control mechanism.
Control mechanism designed to change the height of the blade. It consists of two hydraulic cylinders, with the help of which efforts are created to deepen the blade into the ground, lift it out and fix it.
Hydraulic drive designed to control the position of the working equipment. It provides the creation of the necessary efforts when transferring the working body to the transport or working position, when deepening or lifting the blade of bulldozer equipment. The hydraulic drive circuit does not provide for the simultaneous control of the working body and the bulldozer equipment. The machine is equipped with hydraulic drive elements designed for a pressure of 10 MPa.
The hydraulic drive consists of a hydraulic tank, two hydraulic pumps, a hydraulic panel, and four hydraulic cylinders.
Hydraulic tank installed behind the cab. The level of the working fluid in the tank is measured with a dipstick. The volume of the working fluid should be within 150 liters.
The machine is equipped with two hydraulic pumps of the NSh-32U brand, which are driven by a speed reducer through a gearbox.
Hydropanel installed on the left behind the cab and is designed for compact placement of hydraulic drive controls. Two three-position GA86 / 2 spools for hydraulic cylinders control, a BG52 -14 safety valve, two GA192 electromagnetic valves, one of which controls the operation of the safety valve, and the other is designed to set the hydraulic cylinders to control the working body in a "floating" position when digging a pit, are fixed on the hydraulic panel. To control the pressure, a pressure gauge with a valve is attached to the panel.
Fig. 3. Hydraulic drive diagram MDK-2M:
1 and 19 - hydraulic cylinders of bulldozer equipment, 2 and 11 - three-position spools GA 86/2, 3 and 5 - electromagnetic valves, 4 - safety valve BG 52-14, 6 and 12 - hydraulic cylinders of the working body, 7, 8, 9 and 10 - chokes, 13 - hydraulic filters, 14 and 16 - check valves, 15 and 17 - gear pumps NSh-32U, 18 - hydraulic tank
The performance characteristics of MDK-2M
| Technical productivity in soils of the 2nd, 3rd categories, m 3 / hour | |
| Maximum transport speed, km / h | |
| Average transport speed on unpaved roads, km / h | |
| Weight, t | |
| Overall dimensions in transport position, mm: | |
| Overall dimensions in working position, mm: | |
| Calculation, person | |
| Frequency of maintenance, engine hours: | |
| Labor intensity of maintenance, man-hour: | |
| Fuel consumption, l / h: with an open pit in transport mode |
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| Fuel range, km | |
| Engine power, kW | |
| Dimensions of the developed cut, m | |
| In one pass: | |
| In two passes: depth width | |
| In three passes: | |
| Movement speed when digging a pit, m / h | |
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Travel speed when working with bulldozer equipment in ordinary soil, km / h, no more: |
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| Fuel tank capacity, l | |
| Number of seats in the cockpit, people | |
| Time of transfer of working equipment to working position, min | |
| Time to prepare a car for transportation by rail, h |
MDK-2M operation (video)
(seventies - early XXI century)
Machine for cutting pits MDK-3
(Product 453)
The MDK-3 machine for excavating pits is a further development of the MDK-2m machine and is intended for cutting trenches and shelters for equipment, pits for fortifications (dugouts, shelters, fire structures). The dimensions of the pits: width along the bottom 3.7m., Depth up to 3.5m., Length as required. Classes of developed soils I-IV.
Productivity according to the amount of excavated soil is 500-600 cubic meters. in hour. According to some sources ("Rescuer Handbook" of the Ministry of Emergency Situations), the capacity reaches 800 cubic meters per hour.
When pulling out pits, the excavated soil is laid to one side to the left of the pit in the form of a parapet. If it is necessary to arrange a parapet on both sides for the second pass, it is necessary to change the direction of the fragments. The beginning and end of the pit are gentle ramps with a slope of 15 degrees. Bulldozer equipment allows you to use the machine for backfilling excavations, devices of gentle slopes. The auxiliary equipment is a powerful bulldozer equipment and a ripper for frozen soils, which significantly increased the capabilities of the machine compared to the old one.
Main tactical and technical characteristics of MDK-3
| Basic machine ................................................ .................................................. ....... | multipurpose heavy tractor MTT |
| Machine weight ................................................ .................................................. .......... | 39.5t. |
| Dimensions: | |
| - in transport position | |
| length............................... | 10.22m. |
| 3y23m. | |
| 4.04m. | |
| - in working position | |
| length................................. | 11.75m |
| width............................. | 4.6m. |
| height............................. | 3.25m. |
| Clearance................................................. .................................................. .................. | 2.73m. |
| 42.5cm. | |
| Specific ground pressure .............................................. ..................................... | 0.78 kg / sq. Cm. |
| Minimum turning radius ............................................... .............................. | 2.33m. |
| Maximum angle of ascent ............................................... ................................... | 28 degrees |
| Maximum roll angle ............................................... ........................................ | 15 degrees |
| Maximum fording depth ............................................... .................................. | 1.3m. |
| Cruising range for fuel .............................................. ............................................... | 500 km. or 10-12 hours. work. |
| Maximum travel speed ............................................... ........................ | 65 km / h. |
| Average speed on unpaved roads .......................................... | 30-35 km / h. |
| Performance................................................. .................................................. ... | 500-600 cubic meters / hour |
| Cut off soil layer in one pass ............................................ .......................... | up to 1.75m. |
| Maximum depth of the torn-off pit .............................................. ............. | 3.7m. |
| Width of the torn-off pit ............................................... ................................. | 3.5m. |
| Categories of developed soils ............................................... ......................... | I-IV |
| Crew................................................. .................................................. .................... | 2 persons |
| Cabin capacity ................................................ .............................................. | 5 people |
| Engine................................................. .................................................. .............. | diesel multi-fuel V-shaped В-46-4 |
| Engine power................................................ ................................................. | 520 kw. (710 hp) |
The main difference between MDK-3 and its predecessor is that the excavation is made when the machine moves backwards, due to which the excavation is torn off in a much smaller number of passes, in comparison with the MDK-2. For example, a trench for an MDK-3 tank breaks off in just one pass in just 3-4 minutes.
If MDK-2 removed 30-40 cm soil layer in one pass, then MDK-3 removes 1.75 m.
The cabin is pressurized, equipped with a filter and ventilation unit, due to which the machine can operate on an area contaminated with poisonous and radioactive substances, and the crew (2 people) in the cabin can be without protective equipment. The cab can accommodate up to five people, including the driver. ... Time to prepare the machine for operation 5-7 minutes. There is a place for the installation of the radio station R-123 (tank), but it is not equipped with it. Equipped with a DP-3B radiometer-roentgenometer, a set of PNV (night vision device).
From the author. The radiometer can be considered a vestige of an era when everyone believed that a new World War would be nuclear. The author has always wondered why they put means of measuring radioactive contamination in engineering vehicles? In order for the calculation to quit working and quickly run away from this place? So after all, the contamination zones in nuclear explosions stretch for tens of kilometers. This is the first thing. And secondly, the combat mission must be performed under all conditions. Despite the threat of death. This is the axiom of war. Tough, I would say cruel. But necessary and inevitable. No tribunal will accept the level of radioactivity as a reason for not fulfilling a combat mission. It’s better for the crew not to know that he is doomed.
But clean air in the cockpit is a necessary thing. And the filtering unit is a little useful and necessary thing. When working in a pit, clouds of dust and sand rise into the air. Plus, the exhaust gases from the engine accumulate in the pit. The author himself got into trouble more than once, working at the MDK-2 (January 1970. Radomyshl. Military training in the battalion of equipment for control points), until he realized that it was possible to turn on the FVU.
Sources of
1. Manual on military engineering for the Soviet Army. Military publishing house .. Moscow. 1984
2. Military engineering training. Tutorial. Military publishing house. Moscow. 1982
3. Machines of engineering weapons. Part 4. Basic products. Military publishing house .. Moscow. 1987
4. Rescuer Handbook. VNII GOChS. Moscow. 2006
The machine for digging pits MDK-2M is intended for arranging trenches and storage facilities for equipment, pits for fortifications (dugouts, shelters, fire structures). Pit sizes: width along the bottom 3.5 m, depth up to 3.5 m, length as required. Classes of soils under development - I-IV. Productivity according to the amount of excavated soil up to 350 m3 per hour.
The machine consists of an AT-T tracked tractor (product 409U), the main working body (for digging pits) - a cutter with a thrower and auxiliary bulldozer equipment. The layout diagram of the pit of the machine is determined by the design of the working body and the position of the engines during the digging of the pit. Hollow machine MDK-2 is a multi-pass machine with crumbles along the bottom of the excavation, it comes off. Engine power 305 hp S., Weight 27.3 tons, transport speed up to 36 km / h. The cabin is pressurized, equipped with a filter ventilation unit, thanks to which the machine is capable of operating on terrain contaminated with poisonous or radioactive substances. Moreover, the crew (2 persons) can find in the cockpit without protective equipment. The cab can accommodate up to five people, including the driver. The fuel supply is enough for 500 km or 10-12 hours of work in the soil. The time to prepare the machine for operation is 5-7 minutes. The cockpit provides a place for the installation of the R-123 radio station, but the car is not equipped with it. Equipped with a radiometer-rethngenometer, a set of PNV-57T (night vision device).
The working body is a cross-digging cutter and a thrower; mounted coaxially on one gearbox. The required excavation profile is achieved by using plows and slopes, which are attached to the frame of the working body. The excavation of the ground raised by the thrower is carried out to one side of the machine. To create a parapet on both sides of the pit, it is necessary to change the directions of the machine's working strokes.
Rice. 183. Machine for foundation pits MDK-2
Digging of pits is carried out in layers, in a shuttle way when the machine is moving forward, with the Speed Reducer turned on, the reverse gear is idle. The soil is thrown to the right side of the pit at a distance of up to 10 m and is in the form of a parapet. In one pass of the machine, the deepening is 30-40 cm. A pit measuring 3.5 × 3.4 m is created in six working strokes. During the first three passes, the working stroke is carried out in one direction of the machine movement with the formation of two entrance ramps at an angle of 15 °. With the next three passes, the working stroke is carried out in the opposite direction compared to the previous passes. This changes the direction of the ejection of soil. At the beginning of the pit, due to the work of the main working body, a shallow ramp with a slope of about 15 ° is created. The second ramp is gradually cut off by an auxiliary working body (bulldozer) at an angle of 40-45 °.
After the last pass, you need to plan the bottom of the pit with a bulldozer.
Bulldozer equipment MDK-2 allows to carry out work on leveling the bottom of the pit, backfilling of pits, and shallow slopes. The permissible lateral deviation during machine operation is up to 15 degrees, the ascent / descent angle during machine operation must be up to 28 degrees.
Machine MDK-3 is a further development of the MDK-2M machine and is intended for laying out trenches and storage facilities for equipment, pits for fortifications (dugouts, shelters, fire structures). The dimensions of the pits that come off: width along the bottom of 3.7 m, depth up to 3.5 m, length as required. Soil classes under development -1-IV.
When digging pits, the soil, they dig, is to one side to the left of the pit in the form of a parapet. If it is necessary to arrange a parapet on both sides, after two or three passes, it is necessary to change the direction of digging. Unlike the MDK-2M, the MDK-3 car moves in reverse while digging a pit, digging in one pass a pit up to 1.75 m deep (instead of 30-40 cm in the old car). At the beginning and at the end of the pit there are gentle ramps with an inclination of 15 degrees.
The auxiliary equipment is a powerful bulldozer equipment and a rocket for frozen soils, which significantly increased the capabilities of the machine compared to the old one. The rocket tool allows you to dig frozen and hard soils to a depth of 0.3 m. Bulldozer equipment allows you to use the machine for planning sites before digging pits, leveling and cleaning pits, backfilling fortifications installed in the pit, backfilling funnels, shallow slopes, removing frozen soil, dug by rozpushnik. In addition, the bulldozer can be used for uprooting stumps with a diameter of 20-40 cm.
The formation of wide pits is carried out by 2-3 parallel passes of the machine with a change in the direction of soil ejection.
The permissible side slope during machine operation is up to 15 degrees, the ascent / descent angle during operation is up to 28 °. Productivity in terms of the amount of excavated soil is 500-600 m3 per hour. The MT-T tracked transporter-tractor (product 453) was used as the base chassis. The machine has a total weight of 39 tons (instead of 27.3 tons in MDK-2M), the transport speed of the machine is up to 65 km / h. The cabin is pressurized, equipped with a filter and ventilation unit, so that the machine can operate on an area contaminated with toxic or radioactive substances, moreover, the crew (2 persons) may be in the cockpit without protective equipment. The cab can accommodate up to five people, including the driver. The fuel supply is enough for 500 km or 10-12 hours of work in the soil. Time to prepare the machine for operation 5-7 minutes.
In the cockpit of the vehicle there is a place for the installation of the R-123 radio station (tank), but the MDK-3 is not equipped with it. Equipped with a set of NVD (night vision device).
Rice. 184. Machine for pits MDK-3
Tactical and technical characteristics of the hollow machines
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Technical productivity, m3 / h: |
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in soils of the first and second categories |
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in soils of the second, third categories |
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Average transport speed in dirt roads, km / h |
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Overall dimensions in working position, mm: |
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Calculation, people |
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Frequency of maintenance, engine hours: |
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Labor intensity of maintenance, people / Hour: |
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Fuel consumption, l / h: |
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when digging a pit |
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in transport mode |
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Fuel range, km |
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Engine power, kW |
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Dimensions of the developed excavation, m per one pass: |
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in two passes: |
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in three passes: |
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Movement speed while digging a pit, m / h |
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Travel speed during work |
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bulldozer equipment, km / h, no more |
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in ordinary soil |
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in frozen loosened soil |
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Movement speed during operation with pushing equipment, km / h |
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Travel speed in operating mode with hydrostatic transmission, km / h: in reverse gear |
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in first gear |
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in second gear |
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in third gear |
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Fuel tank capacity, l |
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Cabin capacity, wasps |
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Time of transfer of working equipment to working condition, min |
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When preparing the machine for transportation by rail, h |
Regimental earth-moving machine PZM-2
General device, principle of operation and basic tactical and technical characteristics of EOV-4421
The EOV-4421 excavator is a cyclic excavator. It is designed for mechanization earthworks and loading and unloading works. The excavator is used for digging trenches and ditches in soils of 1-4 categories without loosening, in frozen soils after their preliminary loosening. The presence of a hook suspension allows lifting, lowering and moving various loads.
Rice. 185. EOV-4421 excavator
Tactical and technical characteristics
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Digging performance in soils of the first and second categories: |
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pits, m3 / h |
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trenches, m3 / h |
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Maximum transport speed, km / h |
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Calculation, people |
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Deployment time, min |
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Fuel consumption per 100 km of track, l |
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Fuel range, km |
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The maximum depth of the pit, which is dug with the width along the bottom, m |
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Bucket capacity, m3 |
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Average cycle time, s |
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Maximum cutting force, kN |
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Maximum digging radius, m |
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Maximum bucket emptying height, m |
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Overall dimensions in transport position, mm: |
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Hook block lifting capacity, t |
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The highest lifting height, m |
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Hook outreach, m: |
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the greatest |
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least |
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Hook lifting height, m: |
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in case of a large departure |
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in case of the slightest departure |
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Excavator technical characteristics
Excavator general data
Excavator power plant
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Four-stroke four-cylinder liquid-cooled diesel engine with vortex combustion chamber |
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Rated power at frequency |
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crankshaft rotation 1700 min, hp with |
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Maximum rotational speed crankshaft, min |
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Minimum speed crankshaft, min |
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Fuel used |
Diesel DL, DZ |
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Lubricant applied |
Motor M-6 / 10V |
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Engine weight, unloaded condition in full set, kg |
(GP-11, GP-8) 780 |
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starting motor |
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Two-stroke single-cylinder carburetor with crank chamber blowing |
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Motor power at frequency crankshaft rotation 3500 min, hp with |
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way to start |
electric starter |
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Fuel used |
a mixture of gasoline and oil in a volume ratio of 15: 1 |
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lubricants used |
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motor M10V M10G, M12Y (GP-11) |
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motor M8V or M8B (GP 8) |
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Electrical equipment |
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constant |
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Rated voltage, V |
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Accumulator battery: |
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capacity, ampergodin |
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Hydraulic drive of the working equipment |
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hydraulic pump: |
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double axial piston, variable capacity |
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Maximum productivity, dm3 / min |
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Discharge pressure, MPa (kgf / cm2): |
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the maximum |
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nominal |
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minimal |
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Swing motor |
Radial piston high torque |
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Hydraulic cylinders, mm: |
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handles |
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outriggers |
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Working fluid at ambient temperature: |
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from -40 to + 5 ° С |
Oil VMGZ TU 38-101479-74 |
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from-1-5 to + 40 ° С |
MG-30 oil |
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Substitutes at ambient temperature: |
TU 38-1-01-50-70 |
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from -25 to + 5 ° С |
Spindle oil AU GOST 1642-75 |
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from +5 to + 40 ° С |
Grease IZOA, I20A GOST 20799-75 |
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Chisel structure, principle of operation, main units and mechanisms of an excavator
The main parts of the excavator include the base machine, the cargo frame with outriggers, the slewing ring, the slewing platform, the working equipment power plant, the working equipment, the hydraulic drive, the control and electrical equipment drives.
The basic machine is the KrAZ-255B vehicle, which has some modifications, which were carried out for the installation of an excavator installation. Changes to the chassis of the base car due to the need to reduce its weight and simplify the installation of the cargo frame. In the places where the cargo frame is attached to the car frame, stiffeners are welded into the frame side members. In the front part of the frame there is a rack for fastening the working equipment in the transport position. In connection with the installation of the cargo frame, the location of the receivers, the modified pneumatic system and power equipment of the car have been changed. The left (in the direction) fuel tank has been moved to the cargo frame. The spare wheel container is installed at the front of the load frame. A headlamp is attached to the rear of the base vehicle to illuminate the terrain while reversing.
The cargo frame is designed for installation, slewing ring and unloading (together with outriggers) of the vehicle chassis. The frame is a stamped-welded structure. The main frame elements are two longitudinal beams connected by a row of lumbar inserts. The longitudinal beams end on both sides with brackets for attaching the outriggers and their hydraulic cylinders. On the upper part of the frame, there is a shell made of a mating surface for installing a support-rotary device. To increase the rigidity of the structure, the brackets of the front outriggers are braced.
Outriggers are designed to unload (together with the load frame) the chassis of the car and create the necessary support for the machine during excavation and loading and unloading operations. In the working position, the outriggers are in contact with the soil, while the middle and rear axles are unloaded, and the excavator is hung on four supports and two front wheels, increases its support and allows you to create significant (up to 91 kN) forces on the cutting edge of the bucket. In the transport position, the hydraulic cylinder rods are retracted, and the supports are raised.
The slewing support is designed to rotate the turntable relative to the base machine, as well as to transfer the working forces along the turntable to the cargo frame. The slewing ring consists of bolted rings, rollers and a ring gear.
The rotary platform is designed to accommodate the power plant, the main elements of the hydraulic system, controls, the excavator cab and working equipment. It is a support, withstands all the loads that arise during the operation of the excavator, and through the swing support device is supported on the cargo frame. In front of the platform there is a four-stroke, four-cylinder liquid-cooled diesel engine with a vortex combustion chamber and systems, it is provided by: fuel and air supply, lubrication, cooling and start-up. Rated power of the engine (SMD-14) 55 kW. The power plant is the source of energy for the working equipment. A single-cylinder two-stroke starting engine PD-10U with a gearbox SMD8-19S4V is used to start a diesel engine. The PD-10U engine is started by an ST-350 electric starter.
To facilitate the start of the diesel engine at a low ambient temperature, an electric torch pre-heater is provided.
The work equipment is a return shovel and consists of a unified boom, arm, bucket, hook suspension, bucket cylinder and arm, two boom cylinders, piping and high pressure hoses. The boom is raised and lowered by hydraulic cylinders.
The boom is designed to install a handle with a bucket and hydraulic cylinders on it. It is a one-piece welded structure of a box-type L-shape.
The stick is an elongated, box-shaped welded structure made from rolled steel and made from the same material as the boom.
Rice. 186. Layout diagram of the EOV-4421 excavator
1 - basic machine: 2 - working equipment; 3 - power plant of the working equipment; 4 - turntable: 5 - outrigger support; 6 - support-turning device; 7 - strapping frame
Shlyakhoprokladach BAT-2 is intended for mechanization of engineering work during the laying of column tracks, preparation of military roads in the city.
Shlyakhoprokladach consists of a base - an MT-T tracked chassis, a universal bulldozer, a crane, a baking powder, and a winch.
The tracked chassis shlhaoproklalacha was developed on the basis of the components of the MT-T heavy conveyor-tractor.
Rice. 187. Shlyakhoplokladach BAT-2
The main parts of the tracked chassis are the frame, cab, power plant, transmission, chassis, pneumatic equipment and electrical equipment.
The BAT-M shlakoplayer working equipment includes bulldozer and crane equipment, control mechanisms for bulldozer equipment, a power take-off mechanism, electro-pneumatic and hydraulic drive.
Bulldozer equipment is designed for layer-by-layer cutting and movement of soil. It is hung in front of the machine and can be installed in working or transport position. In the working position, the dozer blade is lowered to the ground. In the case of a transport run by the machine for a distance of up to 5 km, the bulldozer equipment is suspended on a chain. When marching over a distance of more than 10 km, it is concluded by overturning through the cabin onto the platform and fixed.
The main parts of bulldozer equipment are the frame, jog frame, blade and ski.
The crane equipment is designed for mechanization of loading and unloading operations when laying column tracks and dismantling bulldozer equipment. The lifting capacity of the equipment is 2 tons of any boom radius. The maximum lifting height of the hook is 5.3 m at the boom - 1.1 m and 2 m - for the boom of 5.4 m.The speed of lifting and lowering the load by the winch is 0.18 m / s, the boom is 0.37 and 0.22 m / s. Rotational speed of the turntable 1.9 min.
Rice. 188. Shlyakhoploda BAT-M
The main parts are the base machine (IKT engineering wheeled tractor) and working equipment.
The working equipment is designed for loosening and moving soil over short distances. Components of the working equipment are bulldozer equipment, control mechanisms and hydraulic drive.
Bulldozer equipment with a universal blade is designed for layer-by-layer cutting and formation of a soil prism. The dozer equipment includes a blade, a frame and a ski.
When preparing the bulldozer equipment for operation, the blade wings are set to the position required for operation. When the blade is installed in the grader position, an extension is installed on the forward wing, which is fixed to the tractor body in the inoperative position.
The rearrangement of the wings to the bulldozer, shlakopladalny state and their skewing occurs without leaving the calculation from the cockpit.
The width of the blade in the flat-laying position is 3300 mm, in the bulldozer position - 3820 mm, in the grader position - 3240 mm. The angle of installation of the wings in the sliding position is 110 °. Blade height - 1060 mm. The maximum lift of the blade is 1580 mm and the recess is 400 mm. The mass of the working equipment is 2.9 tons. The time for transferring the bulldozer equipment to the working position is 2 minutes.
