As reported in the foreign press in recent years, the Army major NATO countries heavily equipped with tanks of the third post-war generation
(Ml, «Leopard» 2, «Challenger»), which have better mobility than previous generation tanks (M60, «Leopard» 1, «Chieftain»). It is believed that the high mobility is largely due to the use of sufficiently good power plants, is a complex that includes the engine and maintain the system.
The engine of the modern tank, according to foreign experts, should be to provide a high power density of the machine, have small size and weight, be reliable enough when working in a wide range of ambient temperatures (-50 "… 50 ° C) and at overcoming barriers of water tank at the bottom, have a good pick-up, easy to run and consume different types of fuel. In addition, attention is paid to the development of maintainability, reduce the volume and complexity of maintenance of engines and their systems.
In the 70 years abroad have created new tank
The article used materials and illustrations from foreign publications: «I international defense review», «Armada», «Wehrtech-nik», «Military technology".
engines whose power was 900-1100 IPA (1200-1500 hp.), which is almost two times higher than in the previous generation of engines of tanks. As a result, the power density of some combat aircraft reached 25-27 liters. c. / m. A characteristic feature of this stage of development of foreign Tank engine was the creation in the United States gas turbine power plant and the widespread introduction of other NATO countries, four-stroke multi-fuel turbo-piston diesel engines of high performance.
Powerplant American tank Ml «Abrams» together with the hydromechanical transmission form a single power unit arranged in the engine-transmission compartment located in the rear of the hull. AGT-1500 engine capacity of 1100 kW (1500 hp..) Is a three-shaft turbine engine with two independent turbochargers (high and low pressure) and with a free power turbine. Individual multi-fuel combustor mounted tangentially in the housing high pressure compressor diffuser.
Power turbine — axial, two-stage, adjustable nozzle assembly (PCA), the first stage. RSA is designed to improve engine response, improved fuel economy at partial loads and protect the power turbine runaway with a sharp decrease in the load. Maximum speed power turbine 22,500 minutes -When this single-stage planetary gear reduces engine speed on the output shaft to 3,000 min —
The engine is mounted stationary cylindrical drum-plate heat exchanger with a degree of heat recovery on the estimated power (maximum 0.7) 72%. Location around his gearbox and diffuser circular outlet power turbine has allowed developers to make the relatively small size of GTE.
The fuel system has a filling capacity of 1925 liters. Tanks made of plastic material, have a small mass, increased operational and corrosion resistance. To connect with units of tanks used quick-releasable self-locking connection, allowing reportedly replace the engine and the individual units of the power plant without draining fuel. The fuel system used supervisory (hydromechanical elements with electronic control) controller. Ammunition supply of fuel at travel (on set of standard tracks) 4.5 l / km tank provides a cruising range of about 400 km.
The system is equipped with two-stage air purification cyclone-filter air cleaner. Removal of dust from a dust collector by means of compressed air flow portion -otbiraemogo from GTE, while self-cleaning filter is carried out.
The lubrication system of the engine and the transmission is used synthetic oil. Oil tank capacity of 20.8 liters. Engine oil consumption, as reported, is not more than 0.1 l / h.
Cooling system — air.
The special systems of the power plant are diagnostic system and «Broad.» The system of diagnosing of a technical condition of the engine consists of integrated sensors and measuring devices, signal the need for maintenance and repair of the engine. System «Broad» provides bridging tank water obstacles depth of 1.2 m without preparation and a depth of 2.3 m with the preparation.
During the years 1979-1988 on the basis of sea trials of the tank in the design of GTE was amended to reduce fuel consumption, higher reliability, longer service life and reduced maintenance costs and repairs. It was found that the AGT-1500 is almost four times higher service life than the diesel tank M60.
Foreign experts believe that the advantages of the motor Ml tanks are high quality traction, which improves the dynamics of the tank and increases the average speed of its movement. According to the horns, it can reach a maximum speed
73 km / h, and on rough terrain — 48 km / h.
But in both the US and in other countries to supply new supporters tanks turbine engines experiencing stiff competition from companies — developers of diesel engines.
Foreign experts believe that high performance diesel distinguished West-MB-873 Ka501 company MTU, mounted on the tank «Leopard» 2. This 12-cylinder four-stroke V-shaped ancestor-dimensional turbo-piston diesel engine adapted to run on fuel grades. His power 1100 kW (1500 hp.). Forcing the engine is carried out by the installation of two turbochargers and charge air cooler of the two included in the overall cooling system.
A core engine crankcase is made of a lightweight material. Applied cast iron liners, wet type, individual cylinder heads with pre-chamber central location. The pre-chamber mounted fuel injectors and two glow plugs to facilitate starting the engine. Each crank pin crankshaft placed on two adjacent rod. Engine Timing has a lower location of the cam rollers and overhead valves.
Quite a high reliability of the engine is provided through the use of pre-combustion chamber and piston cooling oil. The energy and economic parameters of the engine are given in the table.
The fuel supply to the cylinders is carried out V-shaped plunger pump installed in the collapse of engine blocks. The capacity of the fuel tanks, placed in the niches of the boards and a special compartment and the fighting between the engine compartment, is 1,200 liters.
The air supply for the diesel engine comes in two air cleaner set out on both sides of the engine and connected by short pipes with turbochargers. Air two-stage. First, air passes through the cyclones (primary purification), and then falls on the cassette with two removable filter paper bags (fine purification). Dust from the air by a centrifugal fan driven by an electric motor. The system has the air pollution indicator.
Lubrication system — combined with dry sump, which fixed the oil tank. One intake and two scavenge oil pump section mounted in the lower half of the crankcase. It is integrated and water-oil cooler, which cools the oil. Elements of the system are connected to the internal lubrication channels without pipelines.
Cooling system — liquid, circulating. It provides the engine at full powerful? * At +38 ° C. The liquid is cooled in two annular radiators arranged above the transmission. Inside the radiator placed centrifugal fans driven by hydraulic couplings from the crankshaft. Filling oil clutches controlled by an electronic controller depending on the engine coolant temperature. When driving a tank under the water flooded the heat sink, the fans are switched off.
In the tank, the engine is installed in a single unit with the nodes and transmission systems (its total weight of 5.7 tonnes). As the West German experts, the engine of the tank «Leopard» 2 provides enough good acceleration, and therefore continue to work to improve it.
In the UK, a new tank «Challenger» is 12-cylinder four-stroke V-shaped (V = 90 °) multi-fuel turbo-piston diesel liquid-cooled V-12TCA company «Rolls-Royce». Charging it by two turbochargers with charge air cooling in two air-to-air coolers.
By design features of the engine include the use of thin-specialists of high cast steel housings, adjacent rods to the crankshaft, aluminum alloy pistons cooled by oil, as well as installation on each block of two heads united on three cylinders.
In the cooling system used three radial flow fan disposed vertically at the rear of the power unit of the transmission. Consumption of 75 kW (100 hp.). Fuel tanks capacity of 1,200 liters made of synthetic rubber.
For the main French tank AMX-40 developed 8-cylinder four-stroke (V = 90 °), liquid-cooled diesel engine capacity of 1100 v8x1500 kW (1500 liters. S.), With the pressurization system «Hyperbar.» This system provides a high level of engine boosting the unregulated low compression ratio. In addition to the turbocharger on the engine installed switchable charge air cooler and the secondary combustion chamber (before the turbine). There bypass line for passing part of air cylinder to the exhaust manifold, from which it together with
Note. TC charge air; ‘
— The turbocharger; OHB — Cooler
— Taking into account air cleaners and night vision goggles.
gas flows into the combustion chamber.
Engine v8x1500 has a high charge pressure (Pk = 0.7 MPa), thus limiting the maximum combustion pressure P, cycle compression ratio is taken low — 7-8. Start the engine by using a turbocharger and an additional combustion chamber. After starting the turbocharger air compressed in the compressor and having a high temperature thereby bypassing the cooler is fed into the engine cylinders together with the scrolling of the crankshaft. In partial bypass mode of air and fuel injection in the additional combustion chamber is automatically regulated in specific amounts to provide the necessary characteristics of the engine. The combustion chamber is kept small pilot flame.
The advantages of motor-system pressurisation «Hyperbar» abroad include the possibility of obtaining a high BMEP (over 3 MPa) at a maximum pressure of combustion, R., not exceeding 14 MPa, the favorable behavior of the torque and good acceleration, since the boost pressure supported by high and low load conditions. The disadvantages of this engine is considered the complexity of the design, and low efficiency.
For diesel v8x1500 firm «Turbomeca» created a turbocharger TM-307, having two axial and single-stage centrifugal compressor with a pressure ratio yak = 8 and two-stage axial turbine. In one unit with a turbocharger mounted starter for starting the fuel pump for supplying fuel to the combustion chamber and an additional oil pump turbocharger. Company «Highway» is designed for those new engines plate-cooler core.
Active development in the field of tank power units indicate the intention to increase the foreign experts fighting properties of existing tanks and be ready for future tanks equipping the next generation of powerful modern engines.
Colonel Shantsev, PhD; Colonel A. MIROSHNIKOV