Turbo is actually an air compressor. It uses the exhaust gas from the engine as power to propel the turbine in the turbine chamber (in the exhaust passage). The turbine drives the coaxial impeller. Inside the intake port, the impeller compresses the fresh air sent from the air filter pipe. , and then into the cylinder. When the engine speed is increased, the exhaust gas discharge speed and the turbine rotation speed are also accelerated, the air compression degree is increased, and the engine intake air amount is increased accordingly, and the engine output power can be increased.
The biggest advantage of turbocharging is that it can significantly increase the power and torque of the engine without increasing the engine's displacement. After an engine is fitted with a turbocharger, the maximum output power can be increased by approximately 40% or more compared to the uncharged turbocharger.
With "T" engine maintenance tips
After the engine is pressurized, the structure of the parts needs to be strengthened accordingly. The highest burst pressure and average temperature produced during engine operation will be greatly increased, which will affect the engine's mechanical performance and lubrication performance, and it will also increase the intake air temperature. Therefore, supercharged engines are generally equipped with an inlet cooling device. In order to reduce the intake air temperature, the engine volume and weight will increase accordingly. Therefore, from the aspect of use and maintenance, it is necessary to strengthen the forced maintenance of the engine and pay attention to the correct method of operation. Use the following points should be noted:
1. Can't go by car. After the engine is started, especially during the winter, it should be allowed to idle for a period of time in order to allow the lubricant to lubricate the bearing sufficiently before the supercharger rotor runs at high speed. Therefore, after the start, you must not bang the throttle to prevent damage to the booster seal.
2. Can't turn off immediately. After a long period of high-speed operation of the engine, it shall be idling for 3-5 minutes and then extinguished. When the engine is running, a portion of the oil is supplied to the turbocharger rotor bearings for lubrication and cooling. When the running engine suddenly stops, the oil pressure drops rapidly to zero, the high temperature of the turbine part of the supercharger is transmitted to the middle, the heat in the bearing support shell cannot be rapidly taken away, and at the same time, the supercharger rotor still rotates under inertia and rotates at high speed. Therefore, if the engine suddenly shuts down in the hot engine state, it will cause the oil in the turbocharger to overheat and damage the bearings and the shaft. In particular, it is necessary to prevent sudden flameout after a few feet of throttle.
3. Keep clean. Clean the air filter on time to prevent dust and other contaminants from entering the high-speed rotating compressor wheel, resulting in unstable rotating speeds or increased wear of the bushings and seals. The engine oil and the filter must be kept clean to prevent impurities from entering, otherwise the oil lubrication capacity will drop, causing premature turbocharger scrap. When disassembling the supercharger, it must be kept clean. Each pipe joint must be blocked with a clean cloth to prevent debris from falling into the supercharger and damaging the rotor. Because the supercharger is often operated at a high temperature, its lubricating oil pipeline is subject to high temperature, and the internal oil is liable to have a part of coking, which may cause insufficient lubrication of the supercharger bearing and damage. Therefore, the lubricating oil line must be cleaned after running for a period of time.
4. Always check the operation of the supercharger. Before and after getting out of the vehicle, check the connections of the tubes of the airway to prevent loosening and falling off and causing the turbocharger to fail and the air to enter the cylinder. When it is found that the oil suddenly becomes dirty, and the crankcase pressure rises rapidly; excessive consumption of oil, etc., the turbocharger is likely to fail and must be removed for inspection.
Type of supercharged engine
There are four main categories:
1. Supercharger (Supercharger): The device is on the engine and is connected to the crankshaft of the engine by a belt. Power is obtained from the output shaft of the engine to drive the rotor of the supercharger to rotate, thereby blowing air into the intake manifold.
Advantages: The speed of the rotor corresponds to the engine speed, so there is no lag or lead and the power output is smoother;
Disadvantages: Because it consumes some of the engine power, it will lead to inefficient booster.
2. Exhaust turbocharger system: use the exhaust gas emitted by the engine to achieve the purpose of boosting. The supercharger has no mechanical connection with the engine. The compressor is driven by the turbine driven by the exhaust gas of the internal combustion engine. Generally, the boost pressure can reach 180-200kPa, or about 300kPa, and an additional air intercooler is required to cool the high-temperature compressed air. The domestic car began to be used on the Audi 200 with a displacement of 1.8 in 1998. Later, there were 1.8T Audi A6 and 1.8T Audi A4, and it was 1.8T and 1.8A Bora.
Advantages: Increased efficiency over mechanical boost;
Disadvantages: The engine power output slightly lags behind the opening of the throttle. After the throttle is increased, it usually takes a moment. The engine will have an explosive power outage.
3.Composite pressurization system: It is the combination of exhaust gas turbocharging and supercharging. It is used on high-power diesel engines. The combined supercharged system has a large engine output power, low fuel consumption, and low noise, but its structure is too complex.
4. Airwave booster system: Pulse airwaves of high pressure exhaust gas are used to force the air to compress. This type of system has good low-speed boosting performance, good acceleration, and a wide range of working conditions; however, it is large in size, bulky, and noisy.
At present, the domestic-made vehicles are mainly North and South, Volkswagen and the two manufacturers introduced 1.8T engine models.
Regarding the similarities and differences between the 1.8T engines, the reporter first interviewed Volkswagen China Automotive Co., Ltd., and the other party thought that the problem was more appropriate for the manufacturers to answer, and they could not answer. The reporter then telephoned separately interviewed FAW-Volkswagen Sales Co., Ltd. Audi Products Division Engine Division, FAW-Volkswagen Sales Co., Ltd. Powertrain Engineering Division and Shanghai Volkswagen Sales Co., Ltd. Engine Division product experts, the overall conclusions are as follows.
The same engine is the same kind
According to the experts from the factory, the core technologies of the Bora 1.8T, Passat 1.8T, Audi A6 1.8T, and Audi A4 1.8T are identical. The engine is the same, so the engine is used for power output, component selection and use. It is also consistent or close to maintenance.
However, experts also pointed out that the same "core" does not mean that the performance is the same. The engine will work with different gearboxes, and the overall performance exhibited will be different.
Differences in placement form A4 slightly adjusted
According to experts from the FAW-Volkswagen Sales Co., Ltd. Powertrain Engineering Division, the biggest difference between the Bora engine and the other three models is the horizontal placement in the cabin, while the other three vehicles are longitudinal. This is mainly related to the size of the car. The Passat and Audi are B-class and C-class cars. The car is relatively long. The engine is more suitable for longitudinal placement in the cabin. The Bora is an A-class car with a compact body and the engine is suitable for horizontal placement. This change in engine placement will naturally bring about a corresponding change in the layout of the bottom structure, but it will have no effect on the performance of the engine itself.
As for the four cars, why the Audi A41.8T's maximum power and maximum torque value will be higher than the other three cars, FAW - Volkswagen Sales Co., Ltd. Audi Products Engine Division experts explained that A41.8T in the engine software Adjustments have been made and boost power has increased.
According to different supercharging methods, there are mainly four types of supercharged engines (also referred to as three types): mechanical supercharging, exhaust gas turbocharging, compound supercharging, and airwave supercharging. The first two turbocharged engines have more applications. The supercharged supercharged vehicle models include the Mercedes-Benz C200K and the exhaust turbo-charged models Saab 9-3 2.0T, VOLVO S80 2.5T and VOLVO S80 2.9T6.
Mercedes-Benz C200K supercharger typical
Mercedes-Benz C200K is a small Mercedes-Benz d-class car, the engine is an in-line four-cylinder 1.8 liters displacement, as equipped with a mechanical booster (Supercharger), its power output comparable with the Mercedes-Benz c240's V6 2.6L engine. Its 240N·m maximum torque can be achieved at 3000-4000 rpm, while the maximum torque of the Mercedes-Benz C240 ​​does not appear until 4500 rpm.
According to professional magazine test drive personnel, the supercharger gains power directly from the engine, so the intervention is immediate and the throttle responds quickly. With the on-demand power output, you can hardly feel the difference from a naturally-occupied engine. When the engine speed reaches more than 400 rpm, the car's pushback and acceleration are more pronounced. Accelerated fluency, no hysteresis and sudden explosion, is the advantage of supercharged engines.
Saab 9-3 2.0T exhaust turbo typical
Saab is one of the early manufacturers of turbo-charged turbo engines in the world. After 25 years of development, its exhaust gas turbocharging technology has become even more sophisticated. As a luxury car that emphasizes sports style, Saab 9-3 2.0T this inline four-cylinder exhaust turbo-charged engine can reach a maximum torque of 265N·m at 2500 rpm. This good acceleration at low speed is very practical for daily driving.
According to professional magazine test drive personnel, exhaust turbochargers have low speed and fatigue, and the lack of sudden operation, but Saab 9-3 2.0T acceleration lag has been reduced to a very small, open up with a naturally aspirated engine The difference between cars is not great.
VOLVO S80 2.5T exhaust turbo typical
Volvo's new S80 2.5T engine is designed with advanced design, superior endurance, flexible operation, high fuel efficiency and fast response. The engine is in the form of a transverse five-cylinder turbocharger with a displacement of 2.5 liters, a maximum power of 210hp (equivalent to 154kw)/5000rpm, and a maximum torque of 320N·m/1500-4500rpm. From the output data, it pays more attention to high-speed output. The additional power generated by the turbine increase equals the original 2.5-liter engine to more than 3.0 liters.
The new S80 2.5T is quite smooth at idle and the vibration is quite slight. In fact, this engine is Volvo's latest technology. The CVVT continuously variable valve timing device is installed in the intake and exhaust parts of the engine to ensure that it can respond quickly to changes in the throttle and the state of combustion of the engine. Staying optimal, even when running at low speeds, it provides plenty of driving power.
Typical VOLVO S80 2.9T6 exhaust gas turbocharger
The S80 is the world’s first sedan with a six-cylinder engine with a transverse engine. The new S80 T60 features a six-cylinder, 24-valve, twin-turbocharged, 2.9 aluminum engine with the world’s smallest manual electric transmission The 272 hp (equivalent to 200 kW) power boosted the large luxury sedan to 100 km/h in 7.2 seconds. Even at a speed of 250 km/h, computer-induced traction control and brake distribution The system also allows you to not have to worry about the control of the vehicle stability and the exertion of power. From 1800 to 5,000 rpm, there is a maximum torque output of 380N·m. You have easily exceeded all people in the case that you have not felt the gearbox shift shock.
Tower Crane gear mainly including 19/38/99 teeth gear, bevel gear, Tower Crane Sun Gear, and so on, which are the critical parts of the tower crane reducer. 19 teeth gear and 38 teeth gear are connected with two motor shaft repectively, which are connected with 99 teeth gear. The speed is reduced by the transmission of gears.
Bevel Gear,Tower Crane Sun Gear,Crane Pinion Gear,Tower Crane Transmission Gear,Tower Crane Drive Shaft
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