Tag: grinding of crankpin

MAN Diesel Engine Maintenance & Repair Services

MAN Diesel Engine 9L28-32

RA Power Solutions was approached by a company based in Dubai regarding a problem in crankshaft faced in MAN Diesel Generating set model no. 9L28/32.

The make, model of Engine, and crankshaft details are given below:

 S. NO Crankshaft Details  
1.Engine Make  MAN B&W
2.Engine Model 9L28/32
3.Crank pin Diameter Standard 230 mm
4.Crankpin Bearing Width 98 mm
5.Place of execution of crankshaft repair  Sailing from Port of Jebel Ali Dubai to JNPT port India(Mumbai)

Repair of MAN Engine Model no. 9L28/32 Diesel Generating set Crankshaft

RA Power Solutions deputed two technicians along with an onsite crankshaft grinding machine and technicians boarded the vessel at port of Jebel Ali Dubai. On conducting the inspection following are the main observations of the crankshaft of MAN Engine Model no. 9L28/32 diesel Generating sets.

  • It was observed that the crankpin no. 3 of the AE#02 was damaged. The Bearing material was embedded on the crank pin diameter. After removal of the white metal from the crankpin, the dimension inspection was done and the following was observed:
    • Minimum crankpin diameter observed:  229.44 mm
    • Maximum crankpin diameter observed:  229.83 mm
  • The above readings were observed against the standard diameter of 230.00 mm.
  • The radius fillet and lubricating oil hole profiles were found acceptable with no damage.
  • Deep Bearings line marks were observed on the remaining 8 numbers of crankpins. 
  • All the crankpins were subject to hardness test and crack check by MPI method and no abnormality was observed.
  • All other parameters were observed within limits.  

Successful Crankshaft Repair of MAN Engine Model no. 9L28/32

  • The grinding of crankpin no. 3 was initially undertaken to the undersize of 1.0 mm maintaining the crankpin diameter of 229.00 mm. Since the Bearing line marks were still visible it was decided to grind further. The final size maintained after grinding and polishing was 228.50 mm which is 1.5 mm undersize. 
  • Considering the rough surface finish and bearing line marks all the remaining crankpins were polished while using the state of art crankshaft grinding & polishing machine using the latest polishing media. 
  • The surface finish of less than 0.20 RA value was maintained. 
  • The ship had the 1.5 mm undersize bearing available which was assembled and the engine was put on load.

RA Power Solutions having more than 41 years of experience in extending crankshaft grinding, metal stitching, rebabbitting of bearing, and all the services related to engine repair. We undertake onsite grinding of crankshaft up to 700 mm diameter. 

The main feature of our crankshaft grinding machine is that the grinding & polishing of the crankshaft can be undertaken even while sailing of the vessel. There is no requirement of holding the vessel at the port or at Anchorage.

Hardness checking of crankpin
Hardness checking of crankpin
Crack Check of MAN Engine Model no. 9L28/32
Crack Check of MAN Engine Model no. 9L28/32
Grinding of Crankpin
Grinding of Crankpin
Crankpin after successful repair
Crankpin after successful repair
Crankpin after polishing
Crankpin after polishing
Crankpin after grinding & polishing
Crankpin after grinding & polishing

For more details regarding crankshaft grinding, rebabbitting of bearing, and engine block repair, please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.

Insitu Crankpin Machining | RA Power Solutions

Sulzer model 6RTA Engine was reported damaged on high seas near Mombasa on transit to Sri Lanka. On investigation, it was observed that the connecting rod bolts got sheared damaging the lower and upper engine block and three crankpins of the Crankshaft.

A team of RA Power Solutions technicians having experience in undertaking insitu crankpin machining and a team undertaking repair of crack and damaged engine block by metal stitching and metal locking process was deputed on board a vessel within a short notice as all of them have a seamen passport.

Repair of Engine Block by Metal Stitching Process
Repair of Engine Block by Metal Stitching Process

On preliminary examination, multiple cracks on the upper and lower crack cases of the engine block were observed measuring in totality 2900 mm in terms of length. Three crankpins were damaged developing taper and ovality exceeding more than 1 mm. RA Power Solutions team of technicians worked non-stop and executed the repair of crankpins by an onsite crankshaft grinding machine. All pins were undersized to 1.5 mm due to the damage.

Grinding of Crankpin on Board a Vessel
Grinding of Crankpin on Board a Vessel
Crankpin After Grinding by Crankshaft Grinding Machine
Crankpin After Grinding by Crankshaft Grinding Machine
 

The engine block cracks were repaired by metal locking and metal stitching process. The complete job was executed within 68 hours. The hard work, knowledge, experience, and sincerity of technicians have been very much appreciated by the owners. This achievement was possible due to RA Power Solutions having the latest design of equipment, and experienced technicians having Indian CDC.

For more information on crankpin machining, metal locking and metal stitching process please email us at rajshahani@rapowersolutions.com, or info@rapowersolutions.com, or call us at +91 9582647131 or +91 9810012383.