In this article, we learn what is coupling and the types of coupling.
What is Coupling in Mechanical Engineering?
Coupling is an important mechanical element used to connect two shafts or to connect a driving shaft to a driven shaft.
The main difference between clutch and coupling is that clutch can be engaged or disengaged as per the need of the operator whereas coupling is a fixed element.
Following are the several purposes for which shaft couplings are used in machinery:
1. To provide connection of shafts of two different units like electric motor and machine.
2. To introduce protection against overloads.
3. To reduce the transmission of vibrations and shocks between two connected shafts.
4. To introduce mechanical flexibility between two connected shafts.
5. Sometimes, due to the limitation of space a long shaft is replaced by a number of small pieces of shafts, and then to connect these pieces couplings are used.
Couplings can be used when,
1. Axes of two shafts are collinear.
2. Axes of two shafts are intersecting.
3. Axes of two shafts are parallel and at a small distance apart.
Requirements or essentials of good coupling:
The basic and important requirements of good coupling are as follows:
1. It should transmit full power or there is no loss of power from one shaft to another.
2. It should keep the shafts in perfect alignment or absorb the slight misalignment between them.
3. It should be easy and simple to connect and disconnect.
4. It should be able to operate in any type of operating condition.
5. Its life cycle should be more.
6. It should be easily available at a low cost.
7. It should not have any projecting parts.
Functions of coupling:
It connects the shafts of two different units such as an electric motor and a machine.
It introduces mechanical flexibility between two connected units and tolerates small misalignments between the connecting shafts.
It reduces the transmission of vibrations and shocks between two connected units.
Different Types of Couplings in Mechanical Engineering
Types of Couplings are classified into the following categories:
1. Rigid couplings:
These couplings are used to connect two shafts that are perfectly aligned. These couplings have no flexibility hence the shafts need to be in good alignment, in order to avoid excessive loads on the coupling or shaft bearings. These couplings are simple and inexpensive.
The following are the types of rigid couplings :
1. Muff or sleeve coupling
2. Split muff or clamp or compression coupling
3. Flange coupling
2. Flexible couplings:
These couplings are used to connect two shafts consisting small amount of misalignment which may be lateral or angular. The shock and vibration absorbing capacity of these couplings is more.
Following are the types of flexible couplings :
1. Bushed-pin type coupling
2. Universal or Hooke’s coupling
3. Oldham’s coupling
Difference between Rigid Couplings and Flexible Couplings
| Sr.
No. |
Comparison Parameters | Rigid Coupling | Flexible Coupling |
| 1 | Purpose | To connect two shafts that are perfectly aligned | To connect two shafts having small misalignment |
| 2 | Alignment | Cannot tolerate any
misalignment |
Can tolerate any
misalignment |
| 3 | Shock and vibration | Cannot absorb Shock and vibration | Can absorb Shock and vibration |
| 4 | Deflection | Deflection is less | Deflection is more |
| 5 | Cost | Less expensive | More expensive |
FAQ
Q 1. How many types of couplings or industrial types of coupling?
There are two types of couplings:
- Rigid Couplings
- Flexible Couplings
Q 2. What are the Different Types of Coupling in Mechanical Engineering?
There are two types of coupling in Mechanical Engineering:
- Rigid Couplings
- Flexible Couplings