The document provides an overview of bearings, which are devices that facilitate movement while reducing friction. It categorizes different types of bearings based on their load-handling capabilities, including ball bearings, roller bearings, ball thrust bearings, roller thrust bearings, and tapered roller bearings, along with specialized bearings for specific applications. Each type is designed to handle distinct load types, such as radial or thrust loads, making them essential in various mechanical applications.

1. Danial Sohail
ME-089
Assignment # 1
Machine Design Practical – ME-305
Third year – Mechanical Engineering Department
NED University of Engineering and Technology
B e a r i n g s
A bearing is a device that is used to enable rotational or linear movement, while
reducing friction and handling stress. Resembling wheels, bearings literally enable
devices to roll, which reduces the friction between the surface of the bearing and
the surface it’s rolling over. It’s significantly easier to move, both in a rotary or
linear fashion, when friction is reduced this also enhances speed and efficiency.
Types of Bearings:
Different application require bearings that are designed to handle a specific type of
load, normally bearings are designed to handle Radial or Thrust load or a
combination of two.
A radial load, as in a pulley, simply puts weight on the bearing in a manner that
causes the bearing to roll or rotate as a result of tension.

2. Thrust loads are force that is applied parallel to the bearing's axis. They are also
called axial or linear loads.
Depending upon applications described above, bearing can be divided into
following types, the differences between types of bearings concern load type and
ability to handle weight.
 Ball bearings
 Roller bearings
 Ball thrust bearings
 Roller thrust bearings
 Tapered roller bearings
 Specialized bearings
Ball Bearing:
Ball bearings are extremely common because they can handle both radial and
thrust loads, but can only handle a small amount of weight. They are found in
a wide array of applications, such as roller blades and even cycles, but are
prone to deforming if they are overloaded.

3. Ball Bearing Ball Bearing in cycle rim
Roller Bearing:
Roller bearings are designed to carry heavy loads the primary roller is a cylinder,
which means the load is distributed over a larger area, enabling the bearing to
handle larger amounts of weight. This structure, however, means the bearing can
handle primarily radial loads, but is not suited to thrust loads. For applications
where space is an issue, a needle bearing can be used. Needle bearings work with
small diameter cylinders, so they are easier to fit in smaller applications.
Roller Bearing Roller bearing in gear box

4. Ball Thrust Bearing:
These kinds of bearings are designed to handle almost exclusively thrust loads in
low-speed low-weight applications. Bar stools, for example, make use of ball
thrust bearings to support the seat.
Ball Thrust Bearing Schematic Showing Ball Thrust Bearing in Stool
Roller Thrust Bearing:
Roller thrust bearings, much like ball thrust bearings, handle thrust loads. The
difference, however, lies in the amount of weight the bearing can handle: roller
thrust bearings can support significantly larger amounts of thrust load, and are
therefore found in car transmissions, where they are used to support helical gears.
Gear support in general is a common application for roller thrust bearings.

5. Roller Thrust Bearing Roller Thrust Bearing in Car Transmission
Tapered Roller Bearing:
This style of bearing is designed to handle large radial and thrust loads—as a result
of their load versatility, they are found in car hubs due to the extreme amount of
both radial and thrust loads that car wheels are expected to carry.
Tapered roller bearing
Schematic showing thrust and radial load on tapered roller bearings in car hubs

6. Specialized Bearings:
There are, of course, several kinds of bearings that are manufactured for specific
applications, such as magnetic bearings and giant roller bearings.
 Magnetic Bearings:
Magnetic bearings are found in high-speed devices because it has no moving parts
this stability enables it to support devices that move unconscionably fast.
Magnetic Bearing
 Giant Roller Bearings:
Giant roller bearings are used to move extremely large and heavy loads, such as
buildings and large structural components.
Giant Roller Bearing working principle as used in Earthquake proofing