If you work with heavy equipment, you understand the value of these machines. You need to understand how the parts of your heavy equipment engine work in order to keep them in top condition. Since the engine powers your equipment, it should be your top priority when it comes to inspection, diagnosis, repair, and replacement.
Overview of Heavy Equipment Engines
Heavy equipment is powerful and able to handle demanding tasks in industries such as construction and forestry. Their working conditions require powerful engines that burn gasoline or diesel to produce mechanical energy. Most heavy equipment machinery uses diesel engines for a number of reasons, but primarily because they require more torque. Diesel engines are more powerful and more fuel-efficient than gasoline engines of the same size. Therefore, heavy machinery such as excavators, bulldozers, loaders, and feller bunchers often use diesel engines to provide the necessary power.
Both gasoline and diesel engines utilize internal combustion engines to convert chemical energy into mechanical energy. The engine converts fuel into energy through a series of combustions, but the process is not the same. Gasoline engines use spark plugs to ignite the fuel and air mixture in the combustion chamber. Diesel engines compress air to high pressure before injecting fuel, which explodes in the combustion chamber. So, one of the main differences between these two engine types is that gasoline engines use spark ignition for combustion, while diesel engines use high-pressure compression.
Why do heavy equipment engines use diesel?
We have described the two engine types, but why are diesel engines better suited for heavy equipment?
- Fuel and cost efficiency: Diesel is highly efficient and gets more miles per gallon than gasoline. Over time, this increased fuel efficiency reduces operating costs.
- Superior power: The high density of diesel means it has 15% more energy than gasoline. For heavy equipment, this extra energy translates into superior power.
- Engine durability: Diesel engines are more ruggedly constructed and are suited to extreme working conditions. They also have lower revolutions per minute (RPM), which makes them more durable and last longer.
Heavy Equipment Engine Components
Heavy machinery consists of many parts that work together to make the engine run. In this guide, we will cover the key components of a heavy equipment engine.
1.Alternator
Diesel-powered machinery relies on the alternator to generate the electrical energy needed to run the machine and charge the battery. If the alternator fails, the charge to keep the engine running will not be available, which means the starter motor responsible for initiating the combustion process will not work.
The starter and electrical system rely on the alternator because it converts alternating current (AC) into an electrical charge. This process occurs when the equipment’s engine is running, by rotating a belt connected to the alternator’s rotor. As a result, the alternator works in sync with the engine to provide the power needed for other critical systems, such as the ignition system and fuel injection system. It also charges the machine’s battery.
A quality alternator ensures that the equipment runs smoothly, but if it fails, you will notice signs such as warning lights coming on, electrical faults, lights flickering or dimming, and reduced engine performance. Proper alternator care and maintenance includes repairs and replacements.
2.Engine Cooling Fan
In addition to performance parts, your machine’s engine is equipped with a cooling system to control engine temperature and protect internal parts. Heavy machinery generates a lot of heat. Cooling fans dissipate heat, prevent overheating buildup, and maintain the proper temperature required for the engine to operate properly.
Problems with cooling fans can cause your machine to overheat, affecting its life and performance. You’ll notice signs such as an elevated temperature gauge, an illuminated overheat warning light, and steam coming from around the engine compartment.
Proper care and maintenance of engine cooling components requires a comprehensive maintenance plan. Technicians will inspect fan blades, motors, shrouds, and other components for signs of wear. Cleaning the radiator and the area around it also helps maintain proper airflow and cooling performance.
3.Connecting Rods
Connecting rods are attachments in each cylinder of the engine, each of which is connected to a common crankshaft. These connecting rods quickly convert the reciprocating motion of each piston into rotational motion, transferring force from the piston to the crankshaft.
Connecting rods are made up of several parts that are critical to their function, as well as the function of the engine as a whole. These parts include:
- Small end: The small end of the connecting rod contains the piston pin, which allows the connecting rod to move up and down with the piston in the cylinder.
- Big end: The big end of the connecting rod is connected to the crankshaft and is usually capped or bolted. The cap secures the connection on the big end to facilitate assembly and disassembly during engine maintenance.
- Connecting rod shank: The shank is the middle part of the connecting rod that connects the small end and the big end. It often has design differences that are critical to engine applications. The I-beam design is suitable for heavy loads and high torque applications because it is stronger than its alternative, the H-beam.
- Bearings: Both the small end and the big end of the connecting rod contain bearings that reduce friction and promote smooth movement.
Problems with connecting rods include bending and cracking due to high stress and bearing wear. These factors can cause signs of failure such as engine misfires, knocking noises, engine vibrations and overheating. Proper connecting rod care and maintenance includes regular lubrication and inspection by a technician. Because the connecting rod is under great pressure, it is best to replace it immediately if signs of wear or damage are found.
4.Crankshaft
The crankshaft is one of the most important parts of a heavy equipment engine because it converts the reciprocating motion of the pistons into rotational motion, which drives the wheels and other systems. The structure of the crankshaft is critical to its function, and its components include:
- Crankpins: These pins are attached to the connecting rods and help convert the piston motion into rotational motion.
- Main journals: These cylindrical sections support the weight of the crankshaft and rotate within the engine block.
- Counterweights: The counterweights are located between the crankpins and main journals and provide balance and stability by applying a reaction force to the weight of the connecting rods and pistons, allowing for smooth operation.
- Oil passages: These passages carry oil from the crankpin and main journals to the bearings.
Crankshaft failures are often caused by wear from engine overloading, temperature fluctuations, and inadequate lubrication. If you notice unusual noises, excessive smoke, overheating, or decreased performance in your engine, you may have a problem with your crankshaft. Proper lubrication helps keep your crankshaft in good condition. Still, replacing a worn or broken crankshaft is the best way to avoid engine damage. When it comes to heavy equipment engine parts, you need to choose the highest quality parts to ensure smooth performance and long life.
5.Oil Pump
The oil pump is the heart of a heavy-duty engine’s oil circulation system. Its primary function is lubrication, as it delivers oil at high pressure through oil passages to all of the engine’s moving parts. If the oil level is too low, the engine will be subject to additional friction, causing multiple parts to fail.
Over time, an oil pump may show signs of damage or wear, such as engine overheating, unusual noises, and a flashing engine light. However, you may want to contact a certified heavy equipment technician for a proper engine diagnosis, as these symptoms may also mean other problems. Pay attention to the following points to keep your oil pump in good condition:
- Use the right type of oil
- Make sure the oil level is high enough
- Change the oil frequently
6.Piston
The engine pistons are small but vital components in heavy equipment engines. They convert burning fuel into energy and transmit the power needed to move the vehicle. The gases and pressure from the combustion expand and push against the pistons, and the rapid up and down motion rotates the crankshaft, creating the mechanical energy needed to drive the wheels. Because pistons play an important role in drawing in and compressing the air and fuel mixture, a malfunction can cause many engine problems. Watch for the following signs of piston failure:
- Loss of power: If your machine seems to have lost engine power, a piston failure could be to blame.
- Unusual noises: Like other engine parts, a malfunctioning piston can cause unusual clanking, knocking, or whirring noises.
- Oil consumption: A worn or damaged piston can cause excessive oil consumption.
Following a maintenance schedule, using quality fuel, and handling heavy equipment properly can help protect your engine’s pistons. However, if wear or damage occurs, have a technician remove and replace the piston.
How the Engine Parts Work Together
The basic principles of how the various parts of a diesel engine work together to drive a vehicle are universal. Heavy machinery often uses a four-stroke cycle engine, which means that the engine goes through four piston strokes to complete one cycle.
Here is an overview of how these processes enable an engine to work using different parts:
- Intake stroke: During the intake stroke, the crankshaft moves down, pulling the piston downward, which draws air into the cylinder. The intake air fills the cylinder through the intake valve, completing the intake stroke.
- Compression stroke: When there is air in the cylinder, the valve closes, and the crankshaft then moves upward, pushing the piston upward. This movement compresses the air in the cylinder, generating tremendous pressure and heat. Before the piston reaches top dead center (TDC), the fuel valve opens and sprays fuel into the cylinder. At the end of the compression stroke, the compressed air becomes hot enough to ignite the fuel.
- Power stroke: During the power stroke, the piston head is pulled away from the cylinder head by the hot, expanding gases. The force of the piston and the resulting motion is transferred through the connecting rod, which transmits the force to the crankshaft, which begins to rotate. Because heavy equipment engines are large and have large pistons that can withstand tremendous pressure, they produce a lot of torque during the power stroke. When the piston reaches bottom dead center (BDC), the power stroke ends and the cylinder fills with exhaust gases.
- Exhaust stroke: During the final exhaust stroke, the intake valve closes and the exhaust valve opens, exhausting the engine. The force of the moving parts then pushes the piston to top dead center (TDC), and the exhaust gases are expelled through the exhaust valve.
Create a high-quality maintenance program
Maximum efficiency is critical for workplaces that use heavy equipment. Create a high-quality maintenance program to ensure that components remain in good condition, thereby increasing equipment efficiency. A high-quality maintenance program should include scheduled maintenance, recommended maintenance, and preventive maintenance strategies.
Buy Engine Components and Other Parts from Hyunkook
Our detailed overview of heavy equipment engine components shows the role each part plays in maintaining engine efficiency and equipment uptime.
With heavy equipment failures costing you money, you need to buy reliable engine parts from a dealer you can trust. Hyunkook is a reputable equipment company with over 15 years of industry experience. We are committed to providing quality equipment and parts, exceptional service, and ongoing customer support. Contact us today to speak with an expert!