🔍 Key Concepts

• Types of piston pin (also called gudgeon pin) mounting in internal combustion engines • How many components share the load and provide a bearing surface for each type • Difference between pins fixed to the piston, fixed to the rod, or free to move in both

💭 Think About

• Think about what it means mechanically if the pin can move/rotate relative to the piston bosses AND relative to the connecting rod eye. • Which term would you use when the pin is not rigidly fixed to either the piston or the connecting rod? • For each option, picture whether the pin is locked at one end, both ends, or neither end.

✅ Before You Answer

• Be clear on whether the pin is fixed to the piston, fixed to the connecting rod, or not fixed to either. • Verify which design allows the load to be spread over the largest bearing area (piston bosses plus connecting rod eye). • Eliminate any term that would imply the pin does not serve as a bearing surface in one of those two locations.