Importance of Hardness in Crankshaft


The hardness of crank pin and main journal of crankshaft is of great importance for the satisfactory performance of the crankshaft. In case of low RPM diesel engine, the crankshafts are not hardened and the hardness is achieved by the metallurgical properties. In case of high RPM engine, crankshafts are hardened. The most common process followed by the manufacturers of crankshaft is to go for induction hardening.

Due to seizure of bearings, the temperature goes high and the hardness increases. The increase in hardness makes the crankshaft brittle resulting to the development of crack.

RA Power Solutions Pvt. Ltd. suggests that whenever seizure of bearings takes place it is important that crankshaft hardness is checked and presence of crack should also be checked either by dye penetrant process or Magnaflux.

Author is Managing Director of RA Power Solutions Pvt. Ltd. having almost four decades of hands on experience in providing consultancy, repair and supply of new and reconditioned crankshafts for high capacity diesel engine. More than 2000 crankshaft have been successfully repaired all over the world, some of which were even rejected by reputed engine manufacturers.

Crankshaft Repairs Made Easy

Crankshaft grinding and polishing is an important activity which is required after running of engine for a long time as due wear and tear taper and ovality is created. Again in case of failure of bearing grinding and polishing of crankshaft is required. In olden times it was necessary to remove the crankshaft from the block and send it to the designated workshop for grinding and polishing.

The removal of crankshaft from the block involved disassembly of complete engine, packing and transportation to the workshop resulting to high down time and expensive. RA Power Solutions has developed, design and manufactured on site crankshaft grinding machine which can undertake grinding of crank pins or journals up to the diameter of 700 mm. The machine is capable of maintaining the tolerance within 0.02 mm in terms of taper and ovality. It is very easy to operate and needs minimum training.

The machine is light in weight can be taken to the site. The machine is in two parts and can be inserted in the engine block through the inspection window facilitating grinding of CR Pin without removal of crankshaft. The grinding and polishing is undertaken by same machine. RA Power Solutions suggest to polish and grind if necessary the crankshaft whenever it is open for major overhauling. This will considerably enhance the life of crankshaft, bearing and engine. The machine gets drive from a pneumatic turbine which is again light weight. The drive is also given by a electrical motor where the air supply is not available. The assembly of the machine and its operation can be seen on a YouTube channel

RA Power Solutions has supplied more than 100 machines to the clients based all over the world who are more than satisfied with its performance, quality and ease of operation.

Introduction to RA Power Solutions Pvt. Ltd., India

Company is providing on site repairs of major components of diesel engine, pumps, compressors and all type of rotary equipments mainly crankshaft, engine block, cylinder heads, liners. The repairs are undertaken by trained and experienced technicians equipped with latest breed of specially designed and developed portable machining equipments. Repairs are executed strictly as per the guidelines and tolerances stipulated by the manufacturers. Company is involved in supplying spare parts and supporting equipments used in diesel power plant. The parts and the supporting equipments are directly sourced from the OEMs and are competitively priced. White metal bearings are manufactured as per the drawing or sample. Rebabbitting of old bearing is undertaken by centrifugal process. The white metal used is sourced from the reputed companies and in house facilities for quality checks are in place.