Bearings 2

Question 1

What is the primary function of a bearing?

Answer 1

Bearings allow two parts, like a shaft and housing, to move freely relative to each other.

Question 2

What are the two main types of bearings?

Answer 2

Plain Bearings (sliding motion) and Rolling Element Bearings (rolling motion).

Question 3

What’s unique about Rolling Element Bearings?

Answer 3

They operate with rolling motion, allowing for higher speeds and loads compared to Plain Bearings.

Question 4

Key characteristics of Rolling Element Bearings

Answer 4

Rolling motion, higher speed and load capacity, reduced friction and wear.

Question 5

What types of loads can Rolling Element Bearings handle?

Answer 5

Radial and thrust loads, though specific capacity varies by design.

Question 6

example of a common Rolling Element Bearing

Answer 6

Single Row Deep Groove Ball Bearing - Handles radial and some thrust loads, cannot take misalignment.

Question 7

Cylindrical Roller Bearings

Answer 7

High radial load capacity, does not support thrust loads.

Question 8

Taper Roller Bearing

Answer 8

Withstands thrust load in one direction, good radial load capacity.

Question 9

Thrust Roller Bearing

Answer 9

Designed to withstand thrust loads only, comes in ball or roller types.

Question 10

Needle Roller Bearing

Answer 10

Very small diameter, mainly for radial loads, low thrust load capacity.

Question 11

Bearing Life Calculation

Answer 11

Factor in fatigue due to contact stresses; manufacturers provide statistical data on bearing life.

Question 12

Basic Static Load Rating

Answer 12

Maximum radial load a bearing can handle when not rotating.

Question 13

Basic Dynamic Load Rating

Answer 13

The constant radial load a bearing can withstand for 1 million revolutions.

Question 14

Rated Life of a Bearing

Answer 14

Number of revolutions before fatigue cracking occurs.

Question 15

Bearing Life Calculation Example

Answer 15

Consider factors like bearing type, load ratings, and operational speed to estimate life in hours.

Question 16

Design considerations for Rolling Element Bearings

Answer 16

Consider installation, misalignment, thrust load orientation, lubrication, and material compatibility.

Question 17

Plain Bearings vs. Rolling Element Bearings

Answer 17

Plain Bearings: smaller, cheaper, quieter, more shock-resistant. Rolling Bearings: lower friction, easier lubrication, higher load/speed capacity.

Question 18

What are Seals in Bearings?

Answer 18

Components that keep lubrication in and contaminants out of bearings.

Question 19

Types of Seals

Answer 19

Static Seals (e.g., O-rings, gaskets) and Dynamic Seals (for rotating shafts).

Question 20

Characteristics of Dynamic Seals

Answer 20

Used in moderate to high-speed applications, manage leakage, varying materials and designs.

Question 21

Features of O-Rings

Answer 21

O-Rings are simple, versatile seals used for static and low-speed dynamic applications. They are specified by internal diameter and cross-section.

Question 22

Applications of O-Rings

Answer 22

O-Rings are widely used in various mechanical systems to prevent leaks, especially in static applications or where there is minimal relative motion.

Question 23

Characteristics of Rotating Shaft Seals

Answer 23

These seals are designed for rotating shafts and are often radial lip seals. They are suitable for moderate shaft speeds and can handle temperatures up to 100°C.

Question 24

Use of Reciprocating Shaft Seals

Answer 24

Reciprocating Shaft Seals, such as packings and piston rings, are used in applications with high temperature and low speed. They provide effective sealing by compression in the housing.