Hydraulic distributor GR-520 EK-14, EK-12 GR 520-314.02.520.00 EKA-14, EKA-18

The older brother of the Twax EK family and just a good hard worker. Let's consider what he is and how he differs from his smaller brothers.

Among the products of the Tver plant, the TVEX EK-18 excavator has the highest power indicators. Advantages such as long service life and reliability of the equipment are due to the use of a reinforced metal structure of the supporting part.

Consumers also note the high technical characteristics of the machine; in Russia, the EK-18 is one of the most popular domestically produced models. The company produces a large number of special construction equipment. The hydraulic special vehicle is equipped with pneumatic wheels. The excavator is positioned as a universal, productive, unpretentious, easy-to-maintain equipment for performing earth-moving tasks. Its profitability is due to the availability and low cost of parts and low fuel consumption.

Purpose

The TVEX 18 excavator easily copes with soils of any category, which allows the equipment to be used everywhere. The main work for which the EK-18 is used:

• territory planning;
• loading and unloading of pallet cargo;
• demolition of construction sites;
• quarry work;
• production of excavations - pits, trenches;
• other types of construction and agricultural work.

Produced in Russia, the TVEX EK-18 excavator is unpretentious to operating conditions. It has high performance at high and low temperatures, high humidity, etc. Thanks to such qualities as efficiency, reliability, maintainability and versatility, the excavator has become an indispensable assistant on construction sites and in quarries.

Modifications

There are several modifications of the equipment; the main distinguishing features of each model are the hydraulic system and motor. The latter can be installed foreign or Russian-made. The foreign unit is characterized by higher power, efficiency and long periods between maintenance.

EK-18 modifications:

• standard model EK-18;
• TVEX EK-18-20 is characterized by increased efficiency; a standard working element (bucket) with a capacity of 1 cubic meter is installed on it. m. All equipment components are produced in Russia. The main frame has a reinforced structure, which guarantees high performance when working in harsh conditions. TVEX 18-20 can be equipped with a large number of additional working parts. This modification is considered the most powerful and multifunctional;
• EK-18-30 is the previous model with an improved foreign-made hydraulic system;
• The EK-18-40 has a clamshell grab as a working tool as standard. This special equipment is most often used in logging and scrap metal processing plants. Optionally, this model can be equipped with a lifting cabin (using hydraulics) and a scrap body;
• EK-18-44 is an improved version of the previous model. A hydraulic lifting cabin, a scrap organ, a five-jaw grab with a capacity of 0.65 m3, and a full-rotary rotator are standardly installed here. Its main purpose is loading and unloading of gondola cars, as well as work for which the EK-18-40 modification is intended;
• TVEX EK-18-60 is equipped with a hydraulic propulsion motor jointly produced by Bosch and Rexroth, a hydraulic pump, and a power unit manufactured by Perkins;
• EK-18-90M is the latest development of the manufacturer, in which axles with limited slip differentials are installed, which improves the ability to overcome difficult areas. The steering wheel made in Italy is smaller in size, which creates more comfortable working conditions for the operator. In addition, the cabin has increased rigidity. The power plant is characterized by increased power indicators, which has a beneficial effect on the efficiency of the equipment. Optionally, handles of various sizes are installed; 2.2 m is used as standard. Increasing its length promotes deeper digging, but the capacity of the working body is reduced.

Technical characteristics of the TVEX EK-18 excavator

Specifications

To increase the lifting capacity of TVEX 18, the installation of two boom-lifting hydraulic cylinders and a bucket with a volume of 1 cubic meter is provided. m.

The main technical characteristics of TVEX EK-18 include:

• weight – 18 t;
• capacity of the standard assembly working body – 0.65 m3, 0.77 m3, 1 m3;
• unloading height – from 6.24 m to 6.75 m;
• digging radius – from 8.85 m to 10 m;
• digging depth – from 5.77 m to 6.97 m;
• angle of rotation of the working body – 177 degrees.

The characteristics of heavy construction equipment depend on the modification. The machine demonstrates high performance at ambient temperatures from -40 to +40 degrees. Thus, the excavator can work not only in Russia, but also in other countries.

Engine

D-245 2S2

The high characteristics of TVEX 18 are due to the installation of a powerful D-245 engine with a volume of 4.75 liters. It is a four-stroke, four-cylinder powerplant producing 77 kW or 107 horsepower. It is equipped with a water cooling system and a direct fuel mixture supply system. The rotation speed is 2200 revolutions per minute of operation. Diesel fuel is used, the unit is started using an electric starter. Engine auxiliary components are manufactured in Germany. Modifications can be equipped with a Perkins engine, model 1104C-44TA, with a power of 123 horsepower.

The cylinders of the domestic engine with a diameter of 110 mm are arranged in a row, vertically. The main components of the engine are connecting rods, pistons, cylinder block, cylinder head, flywheel, crankshaft. All of them are serviceable. To improve the performance of the power plant, turbocharging is used, which ensures an increase in torque to a maximum value (386 Nm) and throttle response. The boost force is adjusted by the operator.

To start the engine in cold weather, a pre-start heater made in Germany “Hydronic 10” is provided.

Fuel consumption

It is 236 g/kW per hour of operation, the diesel fuel tank holds 255 liters.

Transmission

Gearbox 1 – flange; 2 – half-coupling shaft; 3, 16 – cuffs; 4, 8, 11, 18,20,23,25 – bearings; 5 – hydraulic motor; 6, 28 – body; 7, 9, 19,24, 26 – gears; 10 – gear shaft; 12, 17,29 – covers; 13 – brake pulley; 14 – brake pad; 15 - finger; 21.27 – coupling halves; 22 – shaft.

The EK-18 gearbox is used to transmit torque from the hydraulic motor to the drive axles; to change gears, turn on/off the front axle and prevent the excavator from spontaneously starting to move (applying the parking brake). The gearbox consists of a hydraulic motor, a 2-speed gear transmission, a gear shift mechanism, and a parking brake. The excavator axles are equipped with pneumatic shoe brakes.

Electrical equipment

Electrical equipment EK-18 is responsible for starting the engine, illuminating the work area if necessary, ventilating the cabin, turning on the light alarm when the special vehicle is moving, and for pre-heating the diesel engine. In addition to the starter, consumers of electricity on this equipment are control and measuring equipment, lighting and signaling equipment, electric fan motors, and a motor heater. All current sources and consumers are connected according to a single-wire circuit, in which the metal structure (“ground”) of the special vehicle serves as the negative wire.

Chassis

The chassis is represented by a wheeled chassis. The excavator is equipped with a hydrostatic gearbox manufactured by the German company ZF, which is characterized by high reliability, long service life and efficiency under any working conditions. This transmission, when working together with the engine, allows the vehicle to move at speeds of up to 20 km/h.

The TVEX 18 excavator moves around the work site autonomously. To transport equipment to a work site, it is necessary to use a tug, and the maximum speed reaches 40 km/h.

The standard assembly includes a blade support and two outriggers, which ensure machine stability.

Hydraulic system

The consumer has the opportunity to buy TVEX EK-18 with various hydraulic systems depending on the modification of the machine. The Russian production system is installed as standard. It is characterized by a power of 50 kW or 70 horsepower. The maximum pressure in the system is 28 MPa, and the pump that creates it pumps 248 liters of hydraulic fluid per minute of operation. The tank designed for hydraulic fluid holds 350 liters.

The modifications are equipped with a joint production system between Bosch and Rexroth.

Hydraulic distributor GR-520 EK-14, EK-12 GR 520-314.02.520.00 EKA-14, EKA-18

Rice. 16. Hydraulic distributor EK-12, EK-14 (GR-520) 1 - plate; 4, 13 — pressure and drain sections; 2, 3, 6, 10, 11, 12, 14, 15 - working sections; 7 - fitting; 8 - bolt; 9 — washer; 16 — docked valve block “OR”; 17 — built-in “OR” valve; 18 - check valve. The EK-12, EK-14 excavator is equipped with a 10-spool hydraulic valve GR-520 (Fig. 16), consisting of a common plate 1 on which 10 sections are mounted. Of these: two central sections are pressure and drain (4, 13), eight sections are working (2,3,6,10,11,12,14,15). The body of plate 1 contains switching power lines and hydraulic control lines with 17 mounted and docked 16 “OR” valves that provide control of the spools. The working fluid from the executive hydraulic motors is also drained through the plate. Check valves 18 (Fig. 16) are built into the pressure channel in the plate at the points where the fluid is supplied to the working sections of the boom, arm, bucket and platform rotation (Fig. 16), which prevent the reverse flow of the working fluid when turned on and under the influence of a reactive load. The pressure-drain sections of the hydraulic distributor EK-12, EK-14 (GR-520) are designed to supply working fluid from 2 adjustable pumps of the pumping unit to the pressure channels in the slab. In the diagram of the hydraulic distributor EK-12, EK-14 (GR-520) (Fig. 17), the “OR” valves mounted in the plate are indicated with an asterisk.

Rice. 17. Diagram of hydraulic hydraulic valve EK-12, EK-14 (GR-520) P - inlet, A and B - outlets, X and Y - control lines, T - drain, Dr - drainage. Rice. 18. Valve “OR” 1 - body; 2, 5 — rings; 3, 6 — bushing; 4 - plug; 7 - ball; 8 — washer; 9 - fitting. Each of the pressure-drain sections consists of housings 1, a two-position spool 2, adjusting 3 and return 4 springs and two covers 5 and 6. Control pressure is supplied to the hole of one cover, and the other is connected to the drain. Safety valves 10 and 11 (Fig. 16) of indirect action are installed in the housing of one of the pressure and drain sections, designed to limit the pressure in the pump from the actuators. The working sections are designed to direct one or two flows of working fluid to the executive bodies. The working sections consist of cast iron bodies 14, 17 and 18 (Fig. 19), three-position spools 15 and 16, springs 3 and 4, covers 5 and 6. The design of the spool 15 in the stroke mechanism section ensures the connection of the working outlets with the drain in the neutral position, in the remaining working sections, in the neutral position of spool 16, the working taps are locked.

Rice. 19. Hydraulic distributor sections EK-12, EK-14 (GR-520) 1, 14, 17, 18 - housing; 2, 15, 16 — spool valves; 3, 4 — springs; 5, 6 — covers; 10, 11 - safety valves; 19 — safety and make-up valve; 20 — make-up valve; 21 - spool stroke limiter. The design of the safety valve is shown in Fig. 20. Fig. 20. Safety valve 1 - protective ring; 2, 8 — rubber ring; 3, 7 — valve; 4, 10 - spring; 5, 9 — bushing; 6 - ring; 11 - nut; 12 — adjusting screw. The return of the spools to the neutral position is carried out by two springs 3 and 4, located in the long cover. The external spring is used to install the spool exactly in the neutral position, the internal (proportional) spring has an axial clearance of 3 mm when the spool is in the neutral position. Safety-feed valves 19 are installed in the sections of the boom, arm and bucket, and feed valves 20 are installed in the sections of the platform turning mechanism. The designs of the safety-feed and feed valves are shown in Fig. 21.

Rice. 21. Safety and make-up valve 1, 5, 7 - protective ring; 2 - ring; 3, 4, 6, 17 — rubber ring; 8 - nut; 9, 13 — spring; 10 — adjusting screw; 11, 16 — bushing; 12, 14, 15 - valve. In the covers of the working sections of the boom, arm and bucket, spool travel limiters 21 are installed, with the help of which you can change the flow area of ​​the line, and, therefore, you can regulate the speed of movement of the working bodies. Adjustment of the speed of turning the handle by the stroke limiters of the spool of the handle sections of the GR-520 hydraulic distributor is carried out as follows: - set the engine speed to medium (1500...1700 rpm), the fuel supply control lever is in the middle position; - screw in the studs of the spool travel limiter on the large covers of the handle sections and the handle extension so that they protrude 5 mm from the nut; - alternately, turning the handle from the uppermost position, with the handle of the control unit fully turned on, turning in or out the studs on both sections of the handle simultaneously by no more than ¼ turn at a time, to achieve such a rotation speed at which the handle will no longer stop in a vertical position and oscillate, but will move evenly from the highest to the lowest position. The hydraulic distributor EK-12, EK-14 (GR-520) operates as follows. The working fluid from two pumps (Fig. 17) is supplied to the pressure spool.

With all spools in a neutral position, the working fluid from inlet P1 passes through the pressure spool body, through the plate, through the overflow spool, through the plate, through the pressure spool to drain T2, and from inlet P2 - through the pressure spool, through the plate - to drain T2 and unites with flow from P1.

When the working spools are turned on: stroke, blade, platform rotation, handle, the overflow spool turns on and disconnects flow P2, thus only one flow P1 operates. When the working spools are turned on: stroke addition, boom, handle, bucket - the pressure spool is turned on and ensures the combination of flows P1 and P2 to the working spools. Hydraulic distributor EO-3323A.07.21.010 The hydraulic control distributor is two-position, consists of a spool 5, a plate 7, a spring 8, a housing 10, fittings 1 and 2, sealing rings 4, 6, 11 and covers 3 and 9. When applying control pressure under the end of spool 5 through fitting 1 (hole B) the spool moves, blocking taps A and B. In this case, taps A1 and B1 are connected to tap C. In the absence of pressure, spring 8 returns spool 5 to its original position, combining lines A with A1 and B with B1.

Rice. 22. Hydraulic distributor EO-3323 1, 2 - fitting; 3, 9 — cover; 4, 6, 11 - ring; 5 - spool; 7 - plate; 8 - spring; 10 - body; 12 - plug

Device

The main advantages of the TVEX EK-18 excavator include:

• ease of management and maintenance work;
• reliability, durability;
• versatility and multifunctionality due to the installation of additional working bodies;
• productivity;
• installation of a high power power unit;
• installation of a comfortable operator seat;
• sustainability;
• installation of an ergonomic operator's cabin with a wide viewing angle, protective barriers against dust and an increased level of safety.

dimensions

Dimensions of the EK-18: 9.4 m x 2.5 m x 3.25 m (5.25 m with the cabin raised). Depending on the modification, the dimensions of the equipment may deviate from those indicated by 0.1 - 0.2 m.

Cabin

The advantages of an excavator cabin include increased safety and ease of use. Operating the TVEX EK-18 excavator is now even easier, and all the operator’s attention is focused not on the controls, but on the work process.

The cabin itself was designed by a Russian manufacturing company. It has a large glass area, excellent vibration insulation, and a heating system is included as standard. Optionally, you can install an air conditioning system, a reduced-size steering wheel with the ability to adjust, a driver's seat with customization for individual characteristics, and a joystick control system.

The position of the operator's cabin relative to the chassis has changed somewhat. Now the entire work site is within sight. This innovation allowed the EK-18 to become a competitor to foreign equipment from world brands. At the same time, the quality/price ratio of the domestic model is several times higher than that of foreign special equipment.

The dashboard includes controllers and controls, the placement of which is carefully thought out. In the cabin of the TVEX EK-18 excavator there are several compartments for things - tools, first aid kit, personal belongings, etc.

Attachments

The equipment is multifunctional and versatile due to the ability to install various attachments. The standard package includes a bucket with a capacity of 0.65 m3 to 1 m3, depending on the modification and length of the handle. TVEX EK-18 goes on sale complete with working parts:

• grabs – loading (5-jaw) for bulk cargo, digging;
• the ripper is used in the development of rocky and frozen soils;
• a hydraulic hammer is necessary for the demolition of concrete and reinforced concrete construction sites or parts thereof, for the development of frozen soils;
• log grabber with the ability to handle loads weighing up to 3 tons. Guarantees high efficiency during loading and unloading operations and storing pallet materials. Additionally, a full-rotation rotator can be installed;
• hydraulic shears are used for cutting metal products and crushing hard materials.