Why Crankpin Bearings Are Important for Marine Diesel Engines?

When it comes to marine diesel engines, every component is critical to ensure smooth operation—including crankpin bearings. These frequently overlooked components are required for connecting rods to revolve smoothly around the crankpin, carry huge loads, and withstand intense combustion forces.

Tri Metal Bearing for Crank Pin and Main Journal
Tri Metal Bearing for Crank Pin and Main Journal

What Are Crankpin Bearings?

A crankpin bearing, which is also referred to as a rod bearing journal, is a precision component that is located between the crankshaft and connecting rod. Its purpose is to facilitate seamless rotation, minimize friction, and reduce wear. Plain or tri-metal varieties are frequently employed in marine applications due to their high-load capacity and durability.

Why Undersized Crankpin Bearings Matter on Ship Engines?

During engine overhauls or crankshaft grinding, standard-size bearings often no longer fit correctly. This raises a serious issue. Suppliers rarely keep undersized bearings in stock, especially for older engine models that manufacturers have discontinued.

Undersize Engine Bearings
Undersize Engine Bearings
Crankpin Bearings of Yanmar Diesel Engine
Crankpin Bearings of Yanmar Diesel Engine

RA Power Solutions: Reliable, Precision Solutions

With over 45 years of global service, RA Power Solutions specializes in:

  • Sourcing tri-metal bearings from reputable manufacturers in the UK, Germany, and Japan
  • Providing custom undersized crankpin and main journal bearings—even for long-discontinued engine models
  • Onsite crankshaft repair services anywhere in the world.

Crankpin Bearings for Different Marine Engines

At RA Power Solutions, we stock and supply standard and undersized crankpin bearings for a wide range of popular marine engines. We design our solutions to fit after crankshaft grinding. They ensure minimal downtime and reliable performance

Engine MakeEngine ModelBearing TypeUndersize AvailabilityApplications
YanmarS185LTri-Metal / Plain0.80 to 2.00 mmMarine propulsion & power plants
Daihatsu5DC-17Tri-Metal0.50 to 4.00 mmAuxiliary engines on ships
MANL28/32Tri-Metal0.50 to 2.00 mmMarine main engines
MAKM32CTri-Metal0.50 to 2.50 mmHeavy-duty marine & industrial

The Role of Crankpin Bearings in Engine Longevity

  • Friction Reduction / Hydrodynamic Function: These bearings utilize an oil film to separate metal surfaces, significantly lowering wear and safeguarding the crankshaft.
  • Load & Shock Absorption: Especially critical in high-load marine engines, these bearings help dampen combustion forces while maintaining alignment.
  • Cost-Effective Maintenance: Designed to be replaceable, they protect expensive components like the crankshaft itself from damage. The alternative—machining new bearing surfaces—would make engine rebuilds far more costly.
crankpin bearing for daihatsu engine
Crankpin Bearing for Daihatsu Engine

For more details of the Crankpin Bearings for Marine Diesel Engines, undersized crankpin bearings, Tri-Metal Bearings, please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

FAQs:

1. What are crankpin bearings in marine diesel engines?

Crankpin bearings support the connecting rod on the crankshaft, reducing friction and wear.

2. Why are undersized crankpin bearings needed?

You need undersized crankpin bearings after crankshaft grinding. Standard bearings no longer fit.

3. Which marine engines use crankpin bearings?

MAK, MAN, Yanmar, and Daihatsu diesel engines commonly use them.

4. How do crankpin bearings extend engine life?

They minimize friction, absorb loads, and protect the crankshaft from damage.

5. Where can I buy crankpin bearings for marine diesel engines?

RA Power Solutions supplies standard, undersized, and custom crankpin bearings worldwide.

Crank Pin Repair on Board a Vessel of Hyundai Diesel Engine – RA Power Solutions

Hyundai Diesel Engine for Repair
Hyundai Diesel Engine for Repair

RA Power Solutions Pvt. Ltd. was called by a shipping company based in Indonesia, reporting the failure of the crank pins of a Hyundai 1.8 MW diesel engine. Our technicians were deputed with a portable crankshaft grinding machine designed and manufactured by us.

On the arrival of our technicians, it was observed that all the 6 CR pins of the Hyundai engine were badly damaged due to the failure of the lubricating oil pump. The initial inspection of crank pins was conducted, comprising calibration for taper and ovality. Hardness test, crack detection by MPI, and deflection checks were also done and recorded.

MPI of Crankpin for Crack Detection is in Process Crank Pin Repair of Hyundai Diesel Engine
MPI of Crankpin for Crack Detection is in Process style=”color: #000000;”>&gt;<em>Crank Pin Repair of Hyundai Diesel Engine

RA Power Solutions Pvt. Ltd. was successful in executing the on site crankshaft grinding of 6 nos. CR pins in a short time of 72 hours. This achievement was possible because of the excellent design of the onsite crankshaft grinding machine developed and manufactured by RA Power Solutions ‘ in-house engineers. A pneumatic turbine with high capacity and the latest design was used, which helped technicians to execute the repairs in a short duration.

CR pins Grinding of Hyundai engine is in Process
CR pins Grinding of Hyundai engine is in Process
CR Pin After Grinding
CR Pin After Grinding
   

RA Power Solutions Pvt. Ltd. is far ahead of its competitors, having more than 45 years of experience and extending the services of diesel engine crankshaft repairs all over the world. To get more information regarding Hyundai diesel engine, Crank Pin Repair, engine bearings for crankpin, in situ grinding crankpins, contact us at rajshahani@rapowersolutions.com or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.