Exam Question
Discuss the consequences of failure to maintain correct clearances in the case of auxiliary diesel engine crankshaft and bottom end bearings. Describe the procedure of taking crankshaft deflection (16)
Class 4 (4th Engineer)
MEKM
📅 Jun 2025
Reference Answer
### **Consequences of Incorrect Bearing Clearances**
Maintaining correct clearances in crankshaft main and bottom end (crankpin) bearings is critical for the reliable operation of an auxiliary diesel engine. These clearances facilitate hydrodynamic lubrication, which serves two primary purposes: creating a load-bearing oil film to prevent metal-to-metal contact and providing sufficient oil flow to dissipate frictional heat. Deviations from the manufacturer's specified clearances lead to severe consequences.
#### **1. Consequences of Insufficient Clearance (Too Small)**
If the bearing clearance is less than the specified minimum, the following issues arise:
Maintaining correct clearances in crankshaft main and bottom end (crankpin) bearings is critical for the reliable operation of an auxiliary diesel engine. These clearances facilitate hydrodynamic lubrication, which serves two primary purposes: creating a load-bearing oil film to prevent metal-to-metal contact and providing sufficient oil flow to dissipate frictional heat. Deviations from the manufacturer's specified clearances lead to severe consequences.
#### **1. Consequences of Insufficient Clearance (Too Small)**
If the bearing clearance is less than the specified minimum, the following issues arise:
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