MAN PrimeServ On-site Recovery has built up a vast bank of experience within in-situ machining of crankpin and main-bearing journals. Regardless of engine size, we apply our expertise to marine applications – both propulsion and power units – as well as propeller shafts.

Our equipment includes a comprehensive range of crankpin machines and main-bearing machining suiting all engine types. We carry out these services daily around the globe.

Crank Pin Recovery Process

Machining of Radii-fillets

Machining of Radii/fillets

Step 1: Rectification of radii/fillets is needed to ensure alignment of the journal surface.

rough-machining-complete

Rough Machining Complete

Step 3: Rough machining completed. The journal is free of hardness and heat cracks

Hand_Dressing_Bluemarking_by_Test_Shell

Hand Dressing & Bluemarking by Test Shell

Step 5: Hand dressing and blue marking to ensure right geometry and contact surface (minimum 70% contact surface according to MAN specification).

machining-of-journal

Machining of Journal

Step 2: Rough machining using orbital lathe running in the machined radii/fillets.

superfinish

Superfinish (Honing)

Step 4: Honing to restore surface condition

after-final-polish

After Final Polish

 

Step 6: The journal is back to original condition. Customized bearings are installed for unrestricted operation of the engine.


Main-journal Repair Process

main-bearing-journal-machining Step 1: Rough machining of journal by milling.

 

Step 2: Machining of radius/fillets

 

Step 3: Honing to restore surface condition 

main-bearing-journal-recovery

Step 4: Hand dressing and blue marking to ensure right geometry and contact surface (minimum 70% contact surface according to MAN specification).

 

Step 5: The journal is back to original condition. Customized bearings are installed for unrestricted operation of the engine