In the field of construction machinery, the excavator is undoubtedly a highly regarded “strongman”, and the engine, as the “heart” of the excavator, its performance directly determines the working efficiency and reliability of the excavator. Understanding the parts and functions of the excavator engine is of vital importance for the correct operation and maintenance of the excavator.
Overview of Excavator Engine
The excavator engine is a power device that converts the heat energy generated by fuel combustion into mechanical energy. It provides strong power support for the excavator’s walking, digging, rotation and other actions. At present, the engines commonly used on excavators are mostly diesel engines. This is because diesel engines have the advantages of large torque, good fuel economy, high reliability, etc., which can adapt to the operation requirements of excavators under various complex working conditions.
From the overall structure, the excavator engine is composed of multiple systems working together, including fuel supply system, intake system, exhaust system, cooling system, lubrication system, ignition system (for gasoline engines, diesel engines have no ignition system) and starting system. These systems work together to ensure that the engine can operate continuously and stably.
The names and functions of the main parts of the excavator engine
1.Engine body assembly
The engine body assembly is the skeleton of the engine, mainly composed of the cylinder block, cylinder head, cylinder gasket, etc. The cylinder block is the installation base of various mechanisms and systems of the engine, and is equipped with cylinders and water jackets; the cylinder head is used to close the top of the cylinder, and together with the piston top and the cylinder wall, it forms a combustion chamber, and valves, injectors and other parts are also installed on it; the cylinder gasket is installed between the cylinder block and the cylinder head to play a sealing role to prevent leakage of gas, cooling water and lubricating oil.
2.Crank-connecting rod mechanism
The crank-connecting rod mechanism is the core mechanism for the engine to achieve energy conversion, and is composed of a piston group, a connecting rod group and a crankshaft flywheel group. The main function of the piston is to bear the gas pressure in the cylinder and transmit the force to the crankshaft through the connecting rod; the connecting rod connects the piston and the crankshaft, converting the reciprocating linear motion of the piston into the rotational motion of the crankshaft; the crankshaft is the power output shaft of the engine, which can convert the reciprocating motion of the piston into rotational motion and drive other working devices of the excavator; the flywheel has the function of storing and releasing energy, which can make the rotational motion of the crankshaft more stable.
3.Valve mechanism
The main function of the valve mechanism is to open and close the intake and exhaust valves according to the working order and working process of each cylinder of the engine, so that fresh air (for diesel engines) or combustible mixture (for gasoline engines) enters the cylinder in time, and exhausts the exhaust gas after combustion in time. The valve mechanism is mainly composed of a valve group and a valve transmission group. The valve group includes valves, valve guides, valve springs, etc. The valve transmission group includes camshafts, tappets, push rods, rocker arms, etc.
4.Fuel supply system components
Diesel tank: used to store diesel.
Diesel filter: Filters impurities and moisture in diesel to ensure that the diesel entering the injection pump is clean, so as to reduce the wear of the injector and other parts.
Injection pump: Pressurizes diesel and delivers diesel to the injector in a timely and quantitative manner according to the working order and load size of the engine.
Injector: Atomizes the high-pressure diesel sent by the injection pump and sprays it into the combustion chamber to fully mix it with the air for easy combustion.
5.Intake system components
Air filter: Filters the air entering the engine and removes impurities such as dust and sand in the air to reduce the wear of cylinders, pistons and other parts.
Intake manifold: Evenly distributes the filtered air to each cylinder.
6.Exhaust system components
Exhaust manifold: Collects the exhaust gas after combustion in each cylinder and guides it into the exhaust pipe.
Exhaust pipe: Exhausts the exhaust gas outside the engine.
Muffler: Reduces the noise generated when the exhaust gas is discharged.
7.Cooling system components
Water pump: forces cooling water to circulate in the cooling system to ensure cooling effect.
Radiator: also known as water tank, used to dissipate the heat absorbed by cooling water into the air to cool the cooling water.
Fan: speeds up the speed of air flowing through the radiator and improves heat dissipation efficiency.
Thermostat: automatically adjusts the flow of coolant entering the radiator according to the temperature of the engine coolant, so that the engine always works at a suitable temperature.
8.Lubrication system components
Oil pump: pressurizes the oil and delivers it to the various friction surfaces of the engine to play a lubricating role.
Oil filter: filters impurities and colloids in the oil to ensure the cleanliness of the oil and extend the service life of the engine.
Oil radiator: when the oil temperature is too high, cool the oil to ensure that the oil has good lubrication performance.
9.Starting system components
The starting system is mainly composed of a starter, a battery, etc. The starter is a device that converts electrical energy into mechanical energy. When starting the engine, the battery provides electrical energy, and the starter drives the engine crankshaft to rotate, so that the engine starts running.
How do the excavator engine components work together?
The various components of the excavator engine do not work in isolation, but cooperate and work together to complete the process of energy conversion and power output.
When the engine is started, the starter in the starting system starts working under the power supply of the battery, driving the crankshaft to rotate. The rotation of the crankshaft drives the piston to reciprocate through the crank-connecting rod mechanism. During the downward intake stroke of the piston, the intake valve of the valve mechanism opens and the exhaust valve closes. After the air is filtered by the air filter, it enters the cylinder through the intake manifold.
Then enters the compression stroke, the intake valve and exhaust valve are closed, and the piston moves upward to compress the air in the cylinder, so that the air temperature and pressure increase. When the piston approaches the top dead center, the injector of the fuel supply system atomizes the high-pressure diesel and sprays it into the combustion chamber. The diesel is mixed with the high-temperature and high-pressure air and quickly ignites and burns by itself. This is the power stroke. During the power stroke, the gas pressure pushes the piston downward, drives the crankshaft to rotate through the connecting rod, and outputs mechanical energy.
After the power stroke, it enters the exhaust stroke, the exhaust valve opens, the intake valve closes, and the piston moves upward to discharge the burned exhaust gas out of the cylinder through the exhaust manifold, exhaust pipe and muffler. In this way, the engine completes a working cycle, and then repeats the above process continuously to continuously output power.
During the entire working process, the cooling system continuously circulates and cools to prevent the engine from overheating; the lubrication system provides lubrication for each moving part to reduce wear; the fuel supply system continuously supplies diesel to ensure the continuous combustion process.
Practical tips for maintaining the efficiency of excavator engines
To maintain the efficient operation of the excavator engine and extend its service life, daily maintenance and maintenance work needs to be done well. Specifically, the following practical tips can be adopted:
1.Regularly replace the engine oil and oil filter
The engine oil will gradually age, deteriorate, and lose its lubricating properties during the operation of the engine. Regularly replacing the engine oil and oil filter can ensure that the engine parts are well lubricated and reduce wear. Generally speaking, it should be replaced after a certain number of working hours or mileage as specified by the engine manufacturer.
2.Keep the air filter clean
A clogged air filter will result in insufficient air entering the cylinder, incomplete combustion, reduced engine power, and increased fuel consumption. Therefore, the air filter should be checked regularly, and the filter element should be cleaned or replaced in time according to the severity of the use environment.
3.Regularly check and maintain the fuel system
Regularly check the diesel tank, diesel filter, injection pump, injector and other components to ensure that the diesel is clean and prevent impurities from clogging the oil circuit. At the same time, pay attention to the quality of the fuel and avoid using inferior fuel.
4.Maintain the cooling system
Regularly check the coolant level of the cooling system to ensure that the level is within the specified range. At the same time, regularly clean the radiator and water tank, remove the scale and debris inside, and ensure the heat dissipation effect of the cooling system. Also check the working conditions of components such as the water pump, fan, thermostat, etc., and repair or replace them in time if any faults are found.
5.Check and adjust the valve mechanism
Check the valve clearance regularly. If the valve clearance is too large or too small, it will affect the performance of the engine. The valve clearance should be adjusted in time according to the regulations of the engine manufacturer to ensure the normal operation of the valve mechanism.
6.Check the starting system and charging system regularly
Check the battery power and electrolyte level, keep the electrodes clean, ensure that the starter and generator are working properly, and ensure that the engine can be started and charged smoothly.
Avoid engine overload: When using an excavator, operate it reasonably according to the operating conditions to avoid the engine being in an overloaded state for a long time, so as not to aggravate the wear of the engine and reduce its service life.
7.Clean the engine regularly
Clean the engine surface regularly and remove oil, dust and other debris in time. This is not only conducive to observing the working conditions of various engine components, but also prevents debris from entering the engine and causing failures.
Conclusion
The excavator engine is a complex system composed of many parts, each of which has its specific function. They work together to provide powerful power for the excavator. Understanding the names, functions and collaborative working principles of the engine components is essential for the correct use and maintenance of the excavator.
By taking practical maintenance tips such as regularly changing the oil and filter, keeping the air and fuel clean, and maintaining the cooling and lubrication systems, the efficiency of the excavator engine can be effectively improved, its service life can be extended, and the failure rate can be reduced, thereby ensuring that the excavator can work efficiently and stably in various operating environments, providing strong support for engineering construction.