Ever wonder! which is the most important part of your vehicle? Engine, battery, suspension systems, and many more will come to your mind. Each component has its role in offering you a smooth and comfortable ride. There is another hero under the hood, you might not know about. Its crankshaft. It is one of the key components of a reciprocating engine. I think most people are unaware of the crankshaft. So, let’s learn, what is a crankshaft.
What is Crankshaft?
A crankshaft is a key mechanical component of the internal combustion engine (ICE). It is a rotating shaft in the ICE whose primary job is to convert the linear motion of pistons to rotational motion. The rotational motion further allows the vehicles to move. Once the engine cylinder fires, it transforms the energy into usable rotational motion to move the car. This makes it one of the key parts for enhancing engine performance and efficiency. Mainly, there are three key functions of the crankshaft-
- To convert linear motion into rotational motion.
- Lubricate the engine by supplying a precise amount of oil.
- To supply power to the piston.
Components of Crankshaft
A crankshaft comprises numerous components which work together to move the wheel. The key components of crankshaft are discussed in detail below-
Main Journals: The main journal of the crankshaft provides a point of attachment to the engine block. Its main job is to hold the crankshaft in the right place, thus allowing the engine block to rotate within the bearing.
Thrust Washers: In the crankshaft, two or more thrust washers are placed along the length of the crankshaft. Thrust washers allow rotational motion and smooth movement. without the thrust washers, the crankshaft would move vertically instead of rotationally.
Crank Pins and webs: The crankpins are generally called rod journals. they are connected with the connecting rods to transfer piston motion to the crankshaft. Furthermore, the crankweb connects the crankpins and main journals.
Flywheel Mounting Flange: This is the point where the flywheel and crankshaft are attached to the engine. It provides a face for mounting the flywheel, thus it is larger than other parts.
Counterweights:
The primary role of counterweights is to provide balance and stability to the crankshaft. For this purpose, these are mounted on the crank web.
Oil passage: Oil passage is also called oil galleries. It is located across the engine block and cylinder head. It is an oil pipe which delivers oil to different parts of the engine.
Working of Crankshaft
All of the components of the crankshaft work together to “turn the power into motion“. When the crankshaft receives linear motion from the pistons, the crankshaft rotates due to the circular motion of crankpins. Furthermore, this rotation is transferred to the transmission system, thus causing motion in the wheels to move the vehicle. Throughout the process, the crankshaft endures high levels of stress which makes it essential to use a highly durable crankshaft.
Types of Crankshaft
The crankshaft plays a critical role in a vehicle, even the engine, considered as the heart of the vehicle, is of no use without it. Selecting the right one for your automotive friend is important in terms of performance and power. There are various types of crankshafts based on design and feasibility with the engine. Let’s explore different types of crankshaft-
Fully Built Shaft
To build the fully built shaft, firstly, each part is produced individually and then assembled. Journals, crankpins, and crank web are forged or cast separately, then mounted using the shrink fit technique. these engines are commonly found in the old car engines. These offer a high level of safety and durability as each part is forged separately. These are ideal for high-performance engines.
Welded Shaft
As its name suggests, a welded shaft is welded to enhance the strength and integrity of the crankshaft. Once the individual pieces are assembled, the crackpins are welded with the main journals. This eliminates the need to perform pre and post-welding treatments. Welded shafts involve the use of different welding techniques like friction welding, semi-automatic submerged arc welding, and preheat and reduce welding speed.
- The friction welding is mainly used on the steel and stainless steel. It does not only provide integrity to the shafts but also reduces the risk of cracks and leaks.
- Semi-automatic submerged arc welding combines the thick walls with join hollow steel shafts. Electric arc welding is also used with this technique.
- The preheat and reduce welding speed technique involves preheating elements above 300 C temperatures and then reducing the welding speed. This allows to manufacture the shafts of high quality.
Forged Crankshaft
A forged crankshaft are highly durable shaft built under extremely high temperatures to increase toughness. these are made by heating the large steel cylinder in high temperature. Once it is melted, it is pressed and twisted into the shape of a crankshaft. Due to this, it has a uniform flowing grain structure. these have fatigue resistance, high strength, and durability. The forged crankshafts are used in heavy industrial applications and in the areas where fatigue life of the crankshaft is a concern.
Solid Single-Piece Crankshaft
In solid single-piece crankshafts, a single solid piece of material is forged and cast to form such types of crankshafts. These are suitable for both high-speed and low-speed engines. They are designed to bear the vibration and heavy loads of the engine. Furthermore, such crankshafts have high endurance power during the process of firing and cyclic tension.
Billet Crankshaft
Similar to a solid single-piece crankshaft, the billet crankshaft is also designed using a single solid piece of material. They are designed using premium alloy steel and thus are highly durable and tough. This makes them a good choice for high-performance applications.
Cast Crankshaft
The cast crankshafts are produced using a one-time shaping process in which the cast iron or other molten material is poured into the mold to create the raw casting. They have less precise grain structure making them unsuitable for high-performance applications. However, it is a reliable and cost-effective solution for the automotive.
Semi-built Shaft
In semi-built crankshafts, not all the parts are made individually. The crank webs are fully forged and then shrank into the bearing journals. As a result, the crank web has a continuous grain structure. This further increases the fatigue strength. These are more flexible and lighter. Such types of crankshafts are used in large marine engines.
Choose the right crankshaft for your vehicle
Choosing the right crankshaft for your vehicle is important as your vehicle’s performance relies on it. It is important to consider several factors before choosing the crankshaft like application area, engine use, RPM, surface strength, material, and weight.
The application area of the crankshaft is the key factor that needs to be considered. The type of crankshaft suitable for you might vary based on the performance required. The engine of high horsepower and RPM requires forged or billet shafts. Also, they vary based on weight and price. The lighter crankshafts are more expensive than the standard crankshafts.
Conclusion
Overall, the crankshaft is like the heart of the engine. Without it, your car will not move an inch. It is important to understand its functioning to optimize the performance of your vehicle. It is important to choose a crankshaft of high quality and durability for efficiency. Also, different factors such as RPM, horsepower, strength material, weight, etc are essential to consider.
Get yourself high-quality crankshafts at JCBL India. We excel in manufacturing and supplying car spare parts that meet international standards. Reach out to us to check our products.
FAQ
What is a camshaft vs crankshaft?
Both a camshaft and a crankshaft are parts of an internal combustion engine but are different from each other. The camshaft is responsible for opening and closing the intake and exhaust valves of the engine to further regulate the air-fuel mixture and exhaust gases. crankshaft, on the other hand, covers the piston’s motion into circular motion to drive wheels.
What is best a forged crankshaft vs steel?
The forged steel is better than the steel crankshaft in terms of strength and toughness, as well as having a high cost. Furthermore, the forged crankshaft is suitable for a variety of applications due to its ability to handle strain and robustness.
What is a crankshaft sensor?
The primary role of the crankshaft sensor is to monitor the positioning and rotational speed of the crankshaft. By taking count of the crankshaft’s speed, it helps the engine control unit to adjust fuel injection timing.
