Virtually all automobile manufacturers are committed to downsizing because it improves efficiency. After all, reducing the displacement of an engine makes it lighter, means there is less mass to be moved, drives down friction losses and ultimately lowers fuel consumption. However, downsizing also makes crankshaft bearings smaller in diameter and width and often harder, too. This places tougher requirements on the surface of the main and pin bearings and their microgeometry. Key issues include contact ratio, roughness, defined convex transverse shapes, roundness and waviness. Another consequence is that the tools and tool holders used in the superfinishing of surfaces need to be narrower. However, they cannot afford to sacrifice any stability. Supfina Grieshaber GmbH & Co. KG is exhibiting at EMO Hannover 2017 with the new Supfina CenPro S and a clear mission. It aims to show visitors how - despite all the stringent requirements - superfinishing production operations can still be highly precise, reliable, cost effective and satisfy tolerances of a few tenths or hundredths of a micrometer for the surfaces and shape of bearings.
"Our new Supfina CenPro S meets all these requirements and delivers optimum, tried-and-tested quality, precision and cost-effectiveness," says Supfina's Managing Director, Oliver Hildebrandt. "It's a small machine, but a big achievement!" This is not least because its design is based on the tried-and-tested Supfina CenPro, which has had a leading global reputation in crankshaft machining for almost two decades and is seeing continuous development and improvement. The CenPro S is the company's response to the consistent application of downsizing principles. As workpieces must not exceed a maximum length of 500 millimeters, it is ideal for machining crankshafts for engines with up to four inline cylinders. Thanks to a stroke up to 100 millimeters (top dead center to bottom dead center) on the pin bearing finishing units and a diameter swing of up to 200 millimeters, the machine can even finish the crankshafts of high-torque V6 and V8 engines.