Crankshaft Types: Bike, Engine, Marine Engine and Facts


In this article “Crankshaft types” and how crankshaft types are related with others facts that will be discuss. In the system of power transmission crankshaft plays a very important role.

The crankshaft is a shaft which is rotate in a motion and transfer piston’s reciprocating motion to rotation motion. The types of crankshaft is listed below,

Detail explanation of Crankshaft types:-

Welded crankshaft:-

The parts of the welded crankshafts such are journals, crank web, crank pin, crank arms are separately manufactured and after that welded with each other. Among the all types of the crankshafts welded crankshaft is stronger and stable. For manufactured the welded crankshaft became very for costly and maintenance is also quite high for this reason in general application the welded crankshaft is not preferred.

Fully built crankshaft:-

In the fully built up crankshaft by its name it define that all components of the fully built crankshaft is manufactured and fabricated separately with taking helping of the pieces of the matter which are multiple separate. The parts which are machined separately they are crankpins, journals and crank webs. The parts are heated and finally artificially shrink fitted together.

When the parts are cooled loosing the excess amount heat the size of the parts are shrink and make a tight grip to each other. The end portion of the connecting rod of the fully built crankshaft is made with a single solid piece of the material.

The making of the fully built crankshaft is easy because small size parts are assembly to make bigger size equipment. The weight of the fully built crankshaft is heavier.

Semi built crankshaft:-

By the name of semi built crankshaft we easily can recognize that the every parts of the crankshaft is not arrange together some of the parts are only constructed and forged together to make a whole crankshaft design. The parts which are shaped, forged, built together in the semi built crankshaft are bearings, crank web. In diesel engine semi built crankshaft is used.

Billet crankshaft:-

With the help o the 4340 alloy steel the billet crankshaft is manufactured. The 4340 alloy made with chromium, nickel, molybdenum and aluminium. The billet crankshaft transfer maximum amount of power to the load. Minimal balancing is required to the billet crankshaft and also it have lowest amount of machining time for this reason in  the system of power transmission this type of crankshaft widely used.

Forged crankshaft:-

By the name of forged crankshaft we easily can recognize that with the help of forging process the forged crankshaft is make. A block of metal or with a single piece of metal the forged and finally crankshaft shaped is given to it. For arranging the all parts of the forged process welding is not required. The engines where need medium speed like generator there only forged crankshaft can be used.

The engines which are bulky and heavy like two stroke engines there forged crankshaft is not suitable al all. Improving the strength of the forged engine induction hardening process is used. It is robust and moderate economical to use.

crankshaft types
Image – Forged Crankshaft;
Image Credit – Wikipedia

Solid single crankshaft:-

From the term of the solid single crankshaft we can recognize that this type of crankshaft is made with solid one single piece of material.  The solid single crankshaft can work in bothlow speed and high speed for this particular reason in multi cylinder engine solid single crankshaft widely used. The end portion of the connecting rod with two pieces of material solid single crankshaft is made. This structure passes through cyclic tension and load during firing.

The solid single crankshaft is stressed for the reasons of axial vibration torsional vibration, misalignment of the main bearing.

Cast crankshaft:-

Cast crankshaft is made with casting malleable iron. In the engines of diesel and petrol cast crankshaft is used in a wide range. The manufacturing cost is very less comparative to the other types of crankshaft and its maintenance cost is also not too high. For improving tensile strength to the cast crankshaft heat preparation is done and for this reason rate of tear and wear is decreases. The lifetime of this crankshaft is also high.

Engine crankshaft types:

The types of the engine crankshaft are listed below,

  1. Billet crankshaft
  2. Forged crankshaft
  3. Cast crankshaft

The crankshaft of the diesel engine is made with alloy steel. For making the crankshaft of the engine at first alloy steel is heated at very high temperature and after that moulded in shape taking the help of forging die. The engine of the diesel have longer stroke comparative to bore diameter, for this particular reason the crankshaft use in the diesel engine larger than the other parts.  Billet crankshaft is use in diesel engine for improving the performance than the other classifications of the crankshaft.

Bike crank set types:

The types of the bike crank set are listed below,

  • Welded crankshaft
  • Fully built crankshaft
  • Semi built crankshaft
  • Billet crankshaft
  • Forged crankshaft

Diesel engine crankshaft types:

The types of diesel engine crankshaft are listed below,

  1. Fully built crankshaft
  2. Semi built crankshaft
  3. Welded crankshaft
  4. Solid single piece crankshaft

Types of crankshaft in marine engine:

The types of crankshafts in marine engine are listed below,

  1. Fully built crankshaft
  2. Semi built crankshaft
  3. Welded crankshaft
  4. Forged crankshaft
Image – Continental engine marine crankshafts,
Image Credit – Wikipedia

Frequent Asked Questions:-

Question: – Explain the causes behind the unbalancing of crankshafts.

Solution: – The causes behind the unbalancing of crankshafts is listed below,

  1. Explosion or crankcase fire
  2. For the reason of torsion and twist is evolved in the crankshaft.
  3. For the reason of power stroke. After completing the power stroke inside the engine the piston of the engine exerted a jerk force inside the crankshaft thus the crankshaft can make rotation.
  4. The motion of the reciprocating of the piston of the engine inside the chamber of the combustion.
Image – Flat-plane crankshaft (red), pistons (gray) in their cylinders (blue), and flywheel (black);
Image Credit – Wikipedia

Question: – Mention the symptoms by which we can recognize the bad conditions of the crankshaft.

Solution: – The symptom by which we can recognize the bad condition of the crankshaft are listed below,

crankshaft types
Image – Schematic of operation of a crank mechanism;
Image Credit – Wikipedia

Noise:-

When the excessive unwanted noise is produce inside the engine that time we can recognize the bad condition of the crankshaft.

Knocking:-

When inside the crankshaft main journal and connecting rod bearing extreme wear is produce that time knocking is appear in the engine of the machine. Knocking is the symptom by which we can recognize the bad condition of the crankshaft.

Difficulty in starting:-

When the system crate problem in starting that time we can recognize the bad condition of the crankshaft.

Excessive vibration of the engine:-

The CKP sensor easily can detect and bounds the generated vibration of the engine of the vehicle to produce stable power input. If unwanted excessive amount of vibration is produce in the engine that helps us to recognize bad condition of the crankshaft.

Stalling and Backfiring:-

When the default position sensor failure of crankshaft is happened that time backfiring and stalling is occur. The CKP sensor failure causes the engine of the system shut down abruptly and after that starting the engine of the system without any reason. The symptom by which we can recognize the bad condition of the crankshaft among them stalling and backing one of them.

Question: – Write the reasons failure behind the diesel engine.

Solution: – The reasons failure behind the diesel engine is listed below,

  1. Misaligned crankshaft
  2. Develop of the cracks on the fillets.
  3. Excessive amount of vibration is appearing for the reason of torsion that can created cracks in the main journals and crankpin.
  4. Excessive speeding of the engine on load.
  5. Stray current or eddy current is passes from the faulty alternator.
  6. Cylinder of the engine is over pressurized for the reason of hydraulic lock for the reason of water leakage in the system’s engine.

Question: – Write the advantages of crankshaft.

Solution: – The advantages of crankshaft is listed below,

  1. Increases the power of the engine
  2. Provides better torque
  3. Greater efficiency
  4. Smooth running

Question: – Write the disadvantages of crankshaft.

Solution: – The disadvantages of crankshaft is listed below,

  1. Failure of bearing
  2. Manufacturing cost is high
  3. Maintenance cost is high
  4. Friction appear more

Indrani Banerjee

Hi..I am Indrani Banerjee. I completed my bachelor's degree in mechanical engineering. I am an enthusiastic person and I am a person who is positive about every aspect of life. I like to read Books and listen to music. Let's connect through LinkedIn-https://www.linkedin.com/in/indrani-banerjee-2487b4214

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