The customer: The customer is India's leading engineering companies with core competencies in diesel & petrol engines, generator sets, and farm equipment. The Company manufactures and markets a wide range of products covering the segments of Diesel Engines, Gasoline Engines, Diesel Pump-sets, Petrol/Kerosene Engines, Gensets, Farm Equipment, Aftermarket Products, and Construction Equipment (International).
The Manufacturing challenge:
Machining of their crankshaft ‘flying arm for 2 of their leading crankshaft models – earlier the machining could not be completed in a single set-up.
A crankshaft—related to crank—is a mechanical part able to perform a conversion between reciprocating motion and rotational motion. In a reciprocating engine, it translates reciprocating motion of the piston into rotational motion; whereas in a reciprocating compressor, it converts the rotational motion into reciprocating motion. In order to do the conversion between two motions, the crankshaft has "crank throws" or "crankpins", additional bearing surfaces whose axis is offset from that of the crank, to which the "big ends" of the connecting rods from each cylinder attach. It is typically connected to a flywheel to reduce the pulsation characteristic of the four-stroke cycle, and sometimes a torsional or vibrational damper at the opposite end, to reduce the torsional vibrations often caused along the length of the crankshaft by the cylinders farthest from the output end acting on the torsional elasticity of the metal.
In customer’s Diesel engine configuration, the crankshaft was containing direct links called flying arms between adjacent crankpins, without the usual intermediate main bearing.
The customer’s crankshaft models are being produced from Forged steels with typical hardness of 285 BHN. The customer was earlier unable to complete this operation in a single set-up and was facing frequent accuracy & productivity-related problems while machining. Also the customer desired a machining cycle time of 10 minutes / component.
The Manufacturing Solution:
After studying the manufacturing problem and the solution, BFW suggested its Horizontal Machining Center with Hydraulic fixture for a single component loading with minimum interchangeable elements.
The machine thus selected – BFW’s MPH 400E Horizontal Machining Centre has a coolant through spindle operating at 16 bar pressure and rotating speeds of 40 – 4,000 rpm.