Deutsch: Kurbelwelle / Español: cigüeñal / Português: virabrequim / Français: vilebrequin / Italiano: albero a gomiti

A crankshaft is a mechanical component used to convert the reciprocating motion of pistons into rotational motion. This transformation is essential in many types of engines and machinery where linear motion needs to be converted into rotational motion to perform work.


In the industrial context, the crankshaft plays a crucial role in various types of engines, including internal combustion engines, steam engines, and many other mechanical systems. It is typically made of high-strength steel or alloy to withstand the immense forces exerted during operation. The crankshaft consists of multiple crankpins, which are offset from the axis of rotation and connected to the pistons via connecting rods.

The primary function of a crankshaft is to convert the up-and-down motion of the pistons into a circular motion that can drive machinery, vehicles, or other equipment. This is achieved through a series of cranks and crankpins, which create the necessary leverage to turn the shaft. Bearings are used to support the crankshaft within the engine block and to ensure smooth rotation.

In terms of history, the crankshaft dates back to ancient times, with early examples found in Roman and Chinese technology. However, its modern design and application were significantly advanced during the Industrial Revolution, when it became a pivotal component in steam engines and later in internal combustion engines.

Special Considerations

In high-performance and heavy-duty applications, crankshafts are subjected to rigorous testing and quality control measures to ensure they can handle the stresses of operation without failure. This includes precision balancing, surface hardening, and the use of advanced materials to enhance durability and performance.

Application Areas

Crankshafts are used in a wide range of industrial applications, including:

  1. Automotive Engines: Essential for converting piston movement into the rotational force that drives the wheels.
  2. Marine Engines: Used in ships and boats to power propulsion systems.
  3. Industrial Machinery: Utilized in compressors, pumps, and other machinery requiring rotational motion.
  4. Aerospace: Applied in aircraft engines where reliability and efficiency are paramount.
  5. Power Generation: Used in generators to convert mechanical energy into electrical energy.

Well-Known Examples

Notable examples of crankshafts in use include:

  • Automotive Industry: The crankshaft in a car’s internal combustion engine.
  • Marine Industry: Crankshafts used in large marine diesel engines for ships.
  • Aerospace Industry: High-precision crankshafts in aircraft engines.
  • Industrial Machinery: Crankshafts in large compressors and pumps used in manufacturing plants.

Treatment and Risks

Crankshafts are prone to several risks, including:

  • Fatigue Failure: Caused by repeated stress cycles leading to cracks and eventual breakage.
  • Wear and Tear: Due to friction and high pressure, leading to the need for regular maintenance.
  • Misalignment: Improper alignment can cause excessive vibration and damage to the engine or machinery.

Regular maintenance, including lubrication, alignment checks, and inspections for cracks or wear, is essential to mitigate these risks and ensure the longevity and reliability of the crankshaft.

Similar Terms

  • Camshaft: Converts rotational motion to reciprocating motion to open and close engine valves.
  • Flywheel: Stores rotational energy and smooths the delivery of power from the engine.
  • Connecting Rod: Connects the piston to the crankshaft, transmitting motion.


A crankshaft is an indispensable component in many types of engines and machinery, responsible for converting reciprocating piston motion into rotational motion. Its applications span across automotive, marine, aerospace, and industrial sectors. Despite the challenges posed by fatigue, wear, and alignment, regular maintenance and advanced materials technology ensure the efficient and reliable performance of crankshafts in various industrial applications.


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