Chapter 2
Bearings and
Lubrication
MED360S_2025
, Overview:
• Introduction to Bearings and Lubrication
• Lubricant Viscosity
• Petroff’s Bearings Equation & Hydrodynamic Lubrication
• Design of Journal Bearings & Its Lubrication
• Rolling Bearings Types & Dimensions
• Selection of Rolling Bearings
• Materials and Lubrication of Rolling Bearings
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,2.1.1 Introduction
• Purpose of Bearings:
• Provide relative positioning and rotational freedom.
• Transmit loads between two parts (e.g., shaft and
housing).
• Purpose of Lubrication:
• Reduce friction, wear, and heating between moving
surfaces.
• Insert a lubricant (liquid, solid, or gas) between surfaces.
• Tribology: Study of lubrication, friction, and wear.
• Types of Bearings:
• Journal Bearings: Sliding bearings.
• Rolling Bearings: Rolling-element bearings (ball, roller).
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, Illustration of types of Bearings
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Bearings and
Lubrication
MED360S_2025
, Overview:
• Introduction to Bearings and Lubrication
• Lubricant Viscosity
• Petroff’s Bearings Equation & Hydrodynamic Lubrication
• Design of Journal Bearings & Its Lubrication
• Rolling Bearings Types & Dimensions
• Selection of Rolling Bearings
• Materials and Lubrication of Rolling Bearings
MED360S_2025 2
,2.1.1 Introduction
• Purpose of Bearings:
• Provide relative positioning and rotational freedom.
• Transmit loads between two parts (e.g., shaft and
housing).
• Purpose of Lubrication:
• Reduce friction, wear, and heating between moving
surfaces.
• Insert a lubricant (liquid, solid, or gas) between surfaces.
• Tribology: Study of lubrication, friction, and wear.
• Types of Bearings:
• Journal Bearings: Sliding bearings.
• Rolling Bearings: Rolling-element bearings (ball, roller).
MED360S_2025 3
, Illustration of types of Bearings
MED360S_2025 4
