Everything You Need to Know About Automotive Crankshafts

Vehicles with internal combustion (IC) engines rely on the coordinated operation of numerous components to function. One of the most vital components of IC engine vehicles is the automotive crankshaft. As a central rotating shaft, it is responsible for driving the vehicle’s wheels by converting the reciprocating motion of pistons into rotational motion.

This blog post explores everything you need to know about automotive crankshafts. It covers their basics, operating principles, and types. Additionally, it highlights the key stats of the automotive crankshaft market and details how artificial intelligence (AI) is transforming the development of modern crankshafts. Keep reading!

Automotive Crankshaft: Overview

An automotive crankshaft is a key component of the automotive transmission. It is responsible for converting the piston’s reciprocal motion into a continuous rotational motion. That way, it generates the required power for the back-and-forth movement of the piston. The significance of the crankshaft is underscored by its connection to both the flywheel and the engine. It forms an integral link in the power transmission system of the machine.

What Are the Key Components of an Automotive Crankshaft?

Below, we explain to you the key components of the crankshaft:

Main Journals: The crankshaft journals offer an attachment point for the engine block. These journals come with bearings that keep the crankshaft in its desired position. The bearings also facilitate the rotation of the engine block. Plain bearings and journal bearings are two main bearing types found in crankshaft main journals.

Counterweights: Counterweights are attached to the crankshaft for balancing the assembly. These weights offset the weight of the connecting rods and counterpins. The use of counterweights helps lower the stress and vibration on the crankshaft while it’s operating.

Flywheel Mounting Flange: The flywheel mounting flange acts as an attachment point between the flywheel and the crankshaft. The crankshaft’s larger flywheel flange part offers a face for mounting the flywheel.

Crank Pin: The crank pin is also known as the rod bearing journal. It is responsible for facilitating a strong connection between the crankshaft and the connecting rod. The crank pin transfers the reciprocating motion of the piston into the crankshaft’s rotational movement.

Crank Web: The crank web facilitates the connection between the main bearing journals and the crankshaft. The crank web experiences twisting forces during operation.

Thrust Washers: Thrust washers are responsible for controlling the axial movement of the crankshaft. They can be found on either side of the main journals. Thrust washers also maintain the correct position of the crankshaft with the engine block.

What’s Driving Automotive Crankshaft Demand?

Our latest analysis reveals the automotive crankshaft market to register sustained growth in the coming years. With a CAGR of 4.1% between 2025 and 2034, the market is projected to reach USD 7.59 billion by 2034.

The rising production of vehicles globally is a key factor fueling the need for automotive crankshafts. The rising emphasis on improving fuel efficiency and the increased use of lightweight materials further drive the industry expansion.

How Does An Automotive Crankshaft Work?

As mentioned above, an automotive crankshaft contains several parts. All these parts work in tandem to enable the movement of the vehicle. Below, we’ve explained to you the working of the crankshaft in a 4-stroke engine:

Piston Movement

The process begins with the up-and-down movement of the pistons in the cylinders of the engine. The combustion of the air-fuel mixture enables the position movement.

Motion Transformation

In the next step, the automotive crankshaft transforms the linear motion of the piston into rotary motion. After transforming, the rotary motion is then transferred to the camshaft.

Compression

The rotary motion received by the crankshaft enables the opening of the inlet valve. That way, it facilitates the entry of the air-fuel mixture into the combustion chamber. Once full, the piston moves in upward motion from the bottom dead center to the top dead center. This, in turn, leads to the compression of the air-fuel mixture. Additionally, the upward movement of the piston results in the closure of the inlet and exhaust valves and completion of the compression cycle.

Ignition

This is the next phase after the compression process. The released heat at the start of the ignition phase pushes the piston in a downward stroke. As the downward motion continues, the linear motion is also transferred by the piston to the connecting rod.

Flywheel Motion

One end of the crank has a flywheel attached to it. Thus, the piston’s linear motion that’s received by the crank is converted into rotary motion. The rotary motion is then transferred to the flywheel and automotive powertrain systems to enable the movement of the vehicle wheels.

Exhaust Stroke

The downward movement of the piston results in the discharge of the exhaust gases from the combustion chamber. The piston’s downward motion is received by the camshaft, thereby opening the exhaust valve.

How AI is Transforming Automotive Crankshaft Production?

The automotive industry is increasingly embracing artificial intelligence (AI) for enabling the efficient production of various components, including automotive crankshafts. AI-powered robots are being increasingly used in various stages of crankshaft production. These robots can perform tasks with improved precision and consistency as compared to human workers. The use of robots is reducing errors and increasing throughput.

AI is also being leveraged for enhanced quality control. AI algorithms have the capability to analyze images and videos of crankshafts to identify defects like cracks and surface imperfections. These algorithms can also provide real-time feedback to operators, enabling them to make quick adjustments and prevent further production of defective parts. Other areas where AI helps in automotive crankshaft manufacturing are predictive maintenance and the optimization of the supply chain.

To Sum It Up

To conclude, the crankshaft is an essential component of internal combustion engine vehicles that enables efficient conversion of linear motion into rotational motion. Understanding the fundamentals of crankshafts is essential for diagnosing issues, optimizing performance, and improving a vehicle’s safety and reliability. Manufacturers in the automotive crankshaft market are increasingly leveraging advanced technologies to develop crankshafts that meet the performance demands of modern vehicles.