Various types, styles, specifications of the coupling, you need to choose different couplings according to the requirements of the transmission system. In this article, I will analyze the differences between the different types of couplings for you.

What is a coupling device?

In short, a coupling is a shafting transmission that connects two axes to transfer motion and torque, and can be combined or separated only after the machine stops turning.

Different types of couplings are based on function

The action of the rigid coupling

Generally, the axle transmission with stable load, high precision and no impact vibration in the working process.

Action of the flexible coupling

Inelastic element coupling

It has a certain ability to compensate for the relative displacement, but not the ability to buffer the vibration reduction.

• Gear couplings: couplings acting on high-torque equipment.
• Universal coupling:a flexible coupling acting to transfer torque between two non-parallel axes.
• Chain coupling: using a common chain at the same time.
• Slider coupling:consists of two half couplings with grooves on the end surface and an intermediate disc with convex teeth on both sides. It is generally rarely used.

Flexible couplings of the metal elastic element

Metal springs of various shapes use elastic deformation to compensate for the relative offset, damping and buffer function of the two axes, which constitute a flexible coupling with different structural properties.

Flexible couplings of non-metallic elastic elements

The elastic elements are made of non-metallic materials such as rubber, polyurethane, and nylon.

Type of the coupling device

The functions and functions of various kinds of coupling in the transmission system are different, but they have the common basic function is to connect the two axes, transfer torque and movement. Coupling is mainly divided into rigid coupling and flexible coupling two categories.

Rigid coupling device

The parts of the rigid coupling are rigidly fixed and connected together, and there can be no relative movement between the parts. Rigid coupling is mainly divided into flange coupling, radial key flange coupling, parallel shaft coupling and clamshell coupling.

Advantages and disadvantages of rigid couplings

Advantages:

• Simple in structure
• Maintenance and manufacturing costs are low
• In light weight
• Ultra low inertia
• High sensitivity

Disadvantages:

• Unable to compensate for the displacement and the relative offset between the two axes
• No vibration reduction and buffer function
• The median accuracy between the two axes is relatively high

Flexible coupling

Flexible couplings are mainly divided into three categories: flexible couplings with non-elastic components, flexible couplings with metal elastic components and flexible couplings with non-metal elastic components. The flexible coupling also has the function of compensating the relative deviation of the two axes, and the elastic coupling has both the compensation ability and the damping and buffering function of different degrees.

Advantages and disadvantages of flexible couplings with inelastic components

It is mainly divided into gear coupling, universal coupling, chain coupling and slide coupling.

Gear coupling

Advantages:

• Small radial size
• Large torque bearing capacity
• Easy to maintain

Disadvantages:

• Is more expensive than other couplings
• Limited flexibility
• Produces noise and vibration

Universal coupling

There are many structural forms such as: cross shaft type, ball cage type, ball fork type and so on. The cross shaft universal coupling is the most widely used universal coupling.

Advantages:

• Is simple in design and relatively easy to install and maintain
• Has a large angular compensation ability
• Has a compact structure
• Transmission efficiency is more efficient

Disadvantages:

• Low torque capacity
• Higher vibration levels may cause wear and tear of the equipment

Chain coupling

Advantages:

• Simple structure, convenient loading and unloading
• Compact and lightweight
• Low requirements on installation accuracy
• Long working life

Disadvantages:

• Is not suitable for machinery with high speed operation and heavy impact load

Slide coupling

Advantages:

• Large transfer torque
• Easy connection and separation

Disadvantages:

• Loud noise
• Work efficiency is low
• Wear speed is fast

Advantages and disadvantages of flexible couplings with metal elastic elements

Mainly divided into diaphragm coupling and snake spring coupling and so on.

Advantages:

• Large load transfer capacity
• Long service life
• Large elastic modulus and high stability

Disadvantages:

• High precision and precise installation requirements

Advantages and disadvantages of non-metallic elastic components flexible coupling

It is mainly divided into elastic sleeve pin coupling, plum coupling and tire coupling.

Advantages:

• Has the advantages of simple structure, low price and convenient installation
• The range of elastic modulus is large
• Small size, good damping performance
• More deformation energy stored per unit volume
• No lubrication required

Disadvantages:

• Low rubber degree, easy to aging deformation
• Poor oil and heat resistance
• Shorter life

The difference between different types of couplings based on application

The rigid coupling is easy to disassemble and widely used. Mainly used in automation equipment, laser equipment machine, non-standard automation, dispensing machine, screw machine and so on.

Flexible coupling category, large amount, is the most commonly used coupling. Mainly used in automotive drive shaft, agricultural, industrial, medical and other heavy machinery, need high torque and vibration reduction capacity of pumps, compressors and automation equipment and other machinery.

FAQ’S

Why do we need couplings?

During mechanical operation, power needs to be transmitted through various transmission devices, provided that these gears must be transmitted when the shaft is connected in parallel. The coupling can make these axes in the same straight line, so as to meet the transmission needs of mechanical products.

Conclusion

In short, the coupling is an important device in the mechanical transmission system. Each type of coupling structure is different, the function of the transmission system is also very different, and the appropriate coupling needs to be selected according to the specific application.