Crankshaft Repair | Crankshaft Grinding | Onsite Crankshaft Machining

RA Power Solutions undertakes Grinding of Crankshaft of High Capacity Engines used in Shipping companies, Power plants and in various other sectors. The company has experience of more than forty years in undertaking successful repairs of Crankshaft and major components. As we are aware Crankshaft is a heart of engine and is most expensive part with limited availability of particular make and model.

Damaged CrankPin of Mirrlees Blackstone Engine
Damaged CrankPin of Mirrlees Blackstone Engine
Inspection of Crankpin Under Process
Inspection of Crankpin Under Process

 

 

 

 

 

 

 

 

RAP expertise lies in repair of crankshaft s which meets with a serious accident like Seizure of bearing. It is generally observed that due to rubbing of bearing steel surface with the CR Pin diameter, excessive heat is generated. Thus there is a increase in Hardness. Every manufacturer specifies the maximum limit of Hardness.

In case of Mirrlees Blackstone K and KV, major series of engine, the normal hardness at the time of manufacturing of crankshaft is between 21.5 to 26 on HRC Scale (241 to 268 on HB scale). It is obvious that after seizure of bearing, the hardness increases even to the level of 45 to 50 HRC.

The Mirrlees Blackstone allows the higher hardness under deviation maximum up to 32 HRC against the standard of maximum  26 HRC. In normal situation as per the manufacturer, the crankshaft  stands rejected as it has far higher Hardness then the stipulated in the manual.

Field Instruction for Crankshaft Rehabilitation of Mirrlees Blackstone Engine
Field Instruction for Crankshaft Rehabilitation of Mirrlees Blackstone Engine

RA Power took the following action to save the Crankshaft.

I.) The Hardness was taken on various spots, not having gap of more than 15 mm.

II.) Hardness was recorded and maximum hardness of 50 HRC was observed.

III.) Since  bearing line marks, taper and ovality on the crank-pin was observed, the grinding was undertaken and CR Pin dia was reduced by 3.5 mm approx.

IV.) The Hardness was reduced and the maximum Hardness of 42 HRC was observed on few spots. Although the 42 HRC Hardness was on higher side, then the maximum limit of 32 HRC specified by the manufacturer. The Crankshaft was accepted under deviation due to following reasons

a)  The higher Hardness was observed in a scattered pattern.

b) The higher hardness was away from the Lubricating Oil Hole and radius fillet of the CR Pin which are considered to be critical Zone

The Crankshaft was accepted and his performance is observed as satisfactory from last more than three and half years.

The saving of Crankshaft from rejection was possible only due to the Experience RA Power solutions has of successful repair of  more than ten thousand crankshaft.

RA Power Solutions undertakes Crankshaft Repair, Crankshaft Grinding and offer Onsite Crankshaft Machines to the repair companies.

Grinding of Crankpin is in Process
Grinding of Crankpin is in Process by RA Power Solutions

Note: The writer of this article is Mr Raj Shahani, Managing Director of RA Power solutions Pvt Ltd.

Website: http://www.rapowersolutions.com/ and he is instrumental in saving  number of Crankshafts from rejection.

Grinding & Repair of Crankpin is in Process
Grinding & Repair of Crankpin is in Process
Finished Crankpin after Grinding & Repair
Finished Crankpin after Grinding & Repair

Crankshaft Grinding Machine- Mobile Machining of Crankshaft

In case of failure of crankshaft or bearing on a vessel/stationary power plant it results to extremely high cost for repairs and with long downtime. RA Power Solutions manufactures and exports onsite and insitu crankshaft grinding, crankshaft machining equipment which saves considerable cost of repair and save time as disassembly of the crankshaft and transport to the workshop is not required.

Portable Crankshaft Grinding Machine
Portable Crankshaft Grinding Machine
The insitu crankshaft grinding machine performs and delivers the same quality standards which are achieved by old designed, conventional bench type crankshaft grinding machine.

Advantage of using RA Power Solutions onsite crankshaft grinding machine and mobile machine:

I) Company having more than 40 years of experience in grinding and repair of crankshafts of high capacity marine and industrial engines and understands the importance of maintaining tolerances as per OEMs.

II) It is a highly advanced technology grinding machine which is designed to take the stress while machining and polishing of crankshaft, crankpin and main journal.

III) Crankshaft Grinding Machine is light weight and compact and can be easily taken to the site all over the world as accompanied baggage.

Crankshaft Grinding Machine Packed For Dispatch
Crankshaft Grinding Machine Packed For Dispatch
Crankshaft Grinding Machine Accessories Packed for Dispatch
Crankshaft Grinding Machine Accessories Packed for Dispatch

IV) Customized tooling adapting to all makes of engine and models. Machine available in the range of 60 mm to 700 mm.

V) Onsite grinding of crankpin and main journal is possible with this grinding tool.
VI) Onsite Crankshaft Machine is easy to operate and training is provided.

VII) Machine body is made from titanium which results to the minimum vibration while in operation. Machine can be used on vessel while sailing.

The company has sold more than 70 machines all over the world. It is highly recommended for repair workshops, power plants, shipping and engineering companies.

For more information, please email us on info@rapowersolutions.com or call us on +91-9582647131

Grinding of Crankshaft on a Moving Vessel
Grinding of Crankshaft on a Moving Vessel
Grinding of Crankshaft in a Power Plant by Crankshaft Grinder
Grinding of Crankshaft in a Power Plant by Crankshaft Grinder
Grinding of Crankshaft on VBlock by Crankshaft Grinding Machine
Grinding of Crankshaft on VBlock by Crankshaft Grinding Machine

Insitu Crankpin Machining

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

Team of RA Power Solutions technicians having experience of undertaking in-situ 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 upper and lower crack case of 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 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, sincerity of technicians have been very much appreciated by the owners. This achievement was possible due to RA Power Solutions having latest design of equipment, experienced technicians having Indian CDC.

For more information, please email us on info@rapowersolutions.com

Crankshaft Grinding Machine for Small Diameter

Onsite grinding of crankshaft without removing it from the engine block is undertaken by taking the reference of radius fillet.

The onsite crankshaft grinding machine is placed on both side of the radius of the crankpin and tool rotates undertaking grinding and polishing of crankshaft. This process of crankshaft grinding by in-situ crankshaft grinding machine is successful generally for the diameter of the crankpin of 200 mm and above having a bearing width of 125 mm minimum.

Crankshaft Grinding Equipment from 30 mm Diameter
Crankshaft Grinding Equipment from 30 mm Diameter
Insitu Crankshaft Grinder
Insitu Crankshaft Grinder

 

 

 

 

 

For the smaller diameter of the crankpin, it is not possible to undertake the grinding by taking the reference of radius fillet due to the space constraints.

RA Power Solutions has introduced a compact, easy to operate onsite crankshaft grinding machine which is suitable for grinding and polishing of small diameters of the crankpin above 30 mm. The crankpin bearing width can be as small as 30 to 40 mm. With this latest technological advance crankshaft grinding machine, it is easy to grind the smaller diameter of the crankpin having smaller crankpin bearing width.

Onsite Grinding Machine for Small Diameter
Onsite Grinding Machine for Small Diameter

The crankshaft grinding machine has the main features of machining, grinding and polishing of the crankpin. The tolerances in terms of taper, ovality, surface finish are maintained far better than the manufacturer’s recommendation.

RA Power Solutions having 4 decades of experience in in-situ crankshaft grinding have executed successfully repair of more than 11,000 crankshaft all over the world and are leaders in this field.

For your requirement of portable onsite crankshaft machine, you may write us on info@rapowersolutions.com

Turbine, Rotor and Alternator Shaft Grinding and Polishing

Failure of bearing due to over load or accident results to development of taper and ovality on turbine, alternator, rotor shaft. In certain cases the deep bearing line marks are developed and bearing surface becomes rough. This needs to be corrected.

Repair of Turbine and Alternator Shaft
                    Repair of Turbine and Alternator Shaft

RA Power Solutions undertake grinding and polishing of crankshaft, rotor shaft, turbine shaft, alternator from last 4 decades. We are the leaders in extending the grinding and repair services. The main features of turbine, alternator, rotor shaft grinding and polishing are as following:

I) Initial inspection of turbine, alternator, and rotor shaft is undertaken by experienced technicians. They carry all latest instruments to check dimensions, hardness, surface roughness, crack detection, taper and ovality. It is of great importance that proper inspection by Qualified and Experienced Engineer is conducted.

II) Latest breed of turbine, alternator, rotor shaft grinding and polishing equipment is available with us having capacity up to 700 mm diameter.

Grinding & Repair of Crankshaft After Major Accident
Grinding & Repair of Crankshaft After Major Accident

III) Onsite grinding and polishing equipment used by RA Power Solutions is light and compact. Easy to carry to site and can be fitted on the damaged diameter of turbine, alternator and rotor shaft. It is important as minimum dis assembly of the parts is required.

IV) The turbine, alternator, rotor shaft grinding equipment is capable of maintaining close tolerance even up to 20 microns with surface finish of 0.15 Ra value which is far better then the international standard.

V) All the repairs of turbine, alternator, and rotor shaft are executed with guarantee.

RA Power Solutions also manufactures new white metal Babbitt bearing up to 1500 mm and rebabbitting of old bearings which get worn out or damage is done.

Grinding of RotorShaft
Grinding of RotorShaft
Grinding of Main Journal on Board a Vessel
Grinding of Main Journal on Board a Vessel

Crankshaft Grinding

Crankshaft grinding is undertaken by RA Power Solutions having four decades of experience in repair of crankshaft. We have technicians who are trained in our workshop giving them the on job training for Grinding of crankshaft and repair of Crankshaft.

Crankshaft Grinding on Board a Vessel
Crankshaft Grinding on Board a Vessel

We use latest design of crankshaft grinding equipment which is vibration free and is capable to maintain close tolerances in terms of taper and ovality. Crankshaft grinding and crankshaft polishing is done in one setting thus reducing the time of crankshaft repair considerably.

Crankshaft Grinding Machine- Vibration Free
Crankshaft Grinding Machine- Vibration Free
Crankshaft Repair
Crankshaft Repair

 

 

 

 

 

 

 

Crankshaft grinding and crankshaft repair is also undertaken on board the vessel and while the vessel is sailing.

Crankshaft Repair by Portable Grinding and Polishing Machine

RA Power Solutions has four decades of experience undertaking grinding and polishing of crankshaft. We can undertake onsite grinding and polishing of crankshaft from 50 mm to 700 mm. Team of experienced technicians are deputed to the site with light weight, portable crankshaft grinding machine. The repair of crankshaft is done without removing the crankshaft from the engine block. This saves time and cost involved in disassembly of crankshaft, packing and transportation of crankshaft to the workshop.

Potable Crankshaft Grinding Machine
Potable Crankshaft Grinding Machine
Crankshaft Grinder
Crankshaft Grinder

 

 

 

 

 

 

 

Worldwide the repair of crankshaft in workshop is outdated. We depute our technicians all over the world with portable equipments for repair of crankshafts. The repair is executed strictly as per the manufacturer’s specifications and tolerances. The crankshaft repairs are guaranteed for satisfactory performance.

Repair of Crankshaft by Crankshaft Grinding Machine
Repair of Crankshaft by Crankshaft Grinding Machine
Crankpin After Grinding of Crankshaft
Crankpin After Grinding of Crankshaft

 

 

 

 

 

 

 

The recent introduction of vibration less portable onsite crankshaft grinding machine facilitates us to execute crankshaft repair while vessel is sailing.

Our technicians have seaman passports and they can board the vessel from one port and disembark from another port. Thus, saving the cost of anchorage or stay at port.

Crankshaft Repair on Board the Vessel
Crankshaft Repair on Board the Vessel
Offshore Grinding of Crankshaft is in Process
Offshore Grinding of Crankshaft is in Process

 

 

 

 

 

 

 

We also manufacture crankshaft grinders which are priced low and easy to operate. These revolutionary machines are recommended for shipping companies, repair workshop heavy engineering company, etc.

For more information, call us on +91 – 124 – 4378292 , +91 9213604692 or email us on rajshahani@rapowersolutions.cominfo@rapowersolutions.com

Insitu Grinding of Crankshaft

Insitu grinding of crankshaft and polishing is offered by RA Power Solutions Pvt. Ltd. for last more than 3 decades. Our experienced technicians reach at site in minimum possible time with Insitu crankshaft grinding machine and undertake crankshaft repair without removing of crankshaft from the main engine.

Insitu Crankshaft Grinding in Process
Insitu Crankshaft Grinding in Process
Crankshaft Grinding
Crankshaft Grinding

 

 

 

 

 

 

 

The Insitu crankshaft grinding is undertaken by light weight portable Insitu crankshaft grinding machine which is operated pneumatically. The equipment is of latest design and is capable to maintain the close tolerance within 20 to 30  microns in terms of  taper and ovality. Onsite crankshaft grinding can also be undertaken while the vessel is sailing. This is possible due to continuous research and development done by our engineers to minimize the vibrations while the vessel is sailing.Our technicians hold valid seamen book and can sail if required.

 

Upper View of Crankshaft Grinding Machine
Upper View of Crankshaft Grinding Machine

The time required for repair that involves crank pin grinding and polishing of crankshaft is minimum due to the latest design of our crankshaft grinding equipment executed by experienced technicians.

We can undertake grinding and polishing of crankshaft up to 700 mm diameter and have executed more than 10,000 repairs in our 36 years of experience world wide.

Onsite Crankshaft Grinding Machine Ready for Dispatch
Onsite Crankshaft Grinding Machine Ready for Dispatch

 

Pneumatic Motor Mounted on Machine
Pneumatic Motor Mounted on Machine

 

 

 

 

Author of this blog is Raj Shahani, Managing Director of RA Power Solutions Pvt. Ltd. He has been working on crankshafts for last more than 36 years. The author had his training with leading crankshaft manufacturers like CKD Skoda in Pilsener Czech Republic , Sidenor in Spain, National Forge in Germany, etc.

Crankshaft Straightening

It is generally observed that in case of failure of crank pin bearing or Main journal bearing, crankshaft loses its alignment. The alignment of crankshaft and its straightness is of great importance. The crankshaft alignment is specified by the manufacturer according to the crankpin diameter,main journal diameter length of crankshaft etc.

Crankshaft Straightening Process of MAN Diesel Engine
Crankshaft Straightening Process of MAN Diesel Engine
Crankshaft Straightening
          Crankshaft Straightening

In case there is a loss of crankshaft alignment, it is observed that main journal bearings fail repeatedly.

RA Power Solutions Pvt. Ltd. undertakes straightening of crankshaft as per the manufacturer’s specifications onsite by peening process. The technicians are experienced and trained to correct the loss of alignment of crankshaft by peening process. The crankshaft is straightened by peening process to the maximum extent and the final correction is done by grinding of main journals incase required.