The lower half of the main bearings are typically held in place by ‘bearing caps’ which are secured to the engine block using bolts. The basic arrangement is for each bearing cap to have two bolts, but some engines may have four or six bolts per bearing cap (often referred to as “four-bolt mains” or “six-bolt mains” engines). The additional bolts result in increased strength, allowing the engine to withstand higher power output or RPM.
So, Bearing caps contain the main bearings of an engine’s crankshaft. As part of their required processing, bearing caps must undergo a tough splitting operation, requiring strong and stable operations. Tooling for bearing cap machining is highly complex and often custom in nature.
1 – Chamfering bearings before splitting
2 – Reliably roughing crank bores
3 – Face milling irregular stock, cast skin and impure surfaces
4 – Combining seal location ad chamfer into one operation
5 – Roughing the outer diameter
6 – Producing spot faces
7 – Drilling numerous holes
8 – Bearing splitting operations
Types of clutches of bearings in the Iran Khodro Casting Industry Company (IKCI Co.)