By Bob Yu | 25 February 2021 | 0 Comments

EA888 engine introduction and high-quality parts supplier

“Volkswagen EA888 engine” is a newly designed engine of Volkswagen. The engine integrates a series of advanced technologies such as in-cylinder direct injection, turbocharging, and variable valve timing to achieve power, economy and environmental protection.

EA888 series engines include 1.8L and 2.0L two displacements: 1.8TSI maximum power is 118kw (160PS)-5000-6200rpm, maximum torque is 250Nm-1500-4500rpm; 2.0TSI maximum power can reach 147kw (200PS)-5100- 6000rpm, the maximum torque is 280Nm—1700-5000rpm.

The mechanical structure of these two displacement engines is basically the same. The difference is the length of the connecting rod between the crankshaft and the piston. The 2.0TSI is shorter than the 1.8TSI connecting rod, and the crankshaft radius is enlarged to increase the displacement. The piston top structure of the two is also different, mainly to adjust the working volume of the combustion chamber, so as to ensure a consistent compression ratio and achieve the same combustion effect.

The EA888 engine is the main model of the middle and high-end models of the Volkswagen Group. It includes two displacements of 1.8L and 2.0L. It integrates a series of advanced technologies such as direct injection, turbocharging, and variable valve timing. Its low-speed torque, good fuel economy and first-class reliability have been widely recognized by the market. The EA888 engine complies with global uniform technical specifications and quality control requirements, and is mounted on Volkswagen's Magotan, CC, Tiguan, Passat, Audi Q5 and other models. [1] 

Intake variable valve timing

EA888 engine adopts intake variable valve timing technology, which can effectively improve intake and exhaust efficiency. The variable valve timing is mainly achieved through a vane-type hydraulic regulator located on the intake camshaft.

The blade regulator consists of an outer shell, an inner blade rotor and a lock pin located inside the blade rotor. The outer casing is fixed with the external timing gear and is driven by the crankshaft. The inner blade is directly fixed to the intake valve camshaft and rotates with it.

The working principle is mainly to control the hydraulic oil in the corresponding pipeline through the camshaft regulating valve to drive the blades in the regulator, and then drive the camshaft to rotate, realize the advance or delay of valve opening and closing, and the adjustable range reaches 60° crankshaft angle.

In-cylinder direct injection system

The fuel supply system is the most critical part of realizing direct injection in the cylinder. To inject fuel into a cylinder with a very high pressure, it must have sufficient injection pressure.

The high-pressure fuel pump is the key link for fuel pressure. The fuel pump of the EA888 engine is a simple single plunger pump, driven by a square (four-point) cam on the intake camshaft. The four-point cam can synchronize the fuel supply stroke of the fuel pump with the corresponding fuel injection process of each cylinder, and the fuel injection uniformity and repeatability of each cylinder is better.

The maximum oil pressure produced by the high-pressure fuel pump is 150bar. According to the requirements of the engine operating conditions, the fuel pressure can be adjusted between 50bar-150bar by adjusting the oil pressure control valve. It adopts a 6-hole injector with a nozzle cone angle of 50°, which is more conducive to the full mixing of gasoline and air.

Water-cooled turbocharging technology

The turbocharger and exhaust pipe of the engine adopt an integrated design, which can reduce the volume and weight of redundant parts to a certain extent, making this system relatively stable and reliable.

The turbocharger cooling system mainly uses the cooling circulation pump to transport the coolant from the auxiliary cooler to the charge air cooler and the exhaust gas turbocharger. It mainly includes two circulation channels, one is through the turbocharger to cool the turbocharging system; the other is through the cooler in the intake manifold to cool the charge air.

Intake manifold flap

By controlling the opening and closing of the flaps of the intake manifold, the charging requirements of the engine under different operating conditions can be met. For example, when the engine is operating at a low speed, the lower intake passage is closed through the intake manifold flap, which can reduce the cross-section of the airflow to increase the airflow velocity. Combined with the special design of the piston crown, it effectively forms a strong intake vortex. Conducive to the formation and atomization of mixed gas.

Similarly, when the engine enters the high-speed working condition and adopts the homogeneous mixture mode, the intake manifold flap opens the lower intake passage to increase the cross-section through which the airflow passes, so as to obtain more intake air and increase the output power of the engine.

Variable displacement oil pump

In the traditional oil pump operation, as the engine speed increases, the oil pressure also increases. The oil pressure is mainly limited by the pressure limiting valve inside the oil pump, but the oil pump is still running at the maximum output. It consumes the power of the engine, and the input energy is converted into heat energy, which accelerates the aging of the oil.

The EA888 engine uses a variable displacement oil pump, which mainly adjusts the oil pressure by adjusting the oil supply of the pump gear. How to achieve this? It is mainly achieved by the relative movement of the two pump gears inside the oil pump. The two pump gears have no displacement (opposite) and the oil supply capacity is maximum; the two pump gears have the maximum axial displacement (offset) and the oil supply is the smallest.

Double counter-rotating balance shaft

The EA888 engine uses double balance shafts, located on both sides of the lower end of the cylinder block, driven by the crankshaft and chain. The centrifugal force generated by the rotation of the two balance shafts is just opposite to the direction of the centrifugal force generated by the crankshaft, which can cancel most of the vibration, thereby enhancing the dynamic balance characteristics of the engine and reducing noise.

The Volkswagen EA888 engine also integrates advanced technologies such as in-cylinder direct injection, water-cooled turbocharging, and variable valve timing. It has lower fuel consumption, emissions and stronger power output. Compared with the EA111 1.4TSI engine, the EA888 engine uses The use of technologies such as dual balance shafts, valve ball rocker arms, and power-generating and starting integrated machines make the engine run smoother and further reduce noise.

 

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