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What is the difference between flexible coupling and rigid coupling?
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What is the difference between flexible coupling and rigid coupling?

Views:0     Author:Site Editor     Publish Time: 2021-04-29      Origin:Site

There are two main types of couplings: rigid couplings, which connect two shafts with a solid and high-precision hold, and flexible couplings, which can be used to connect slightly misaligned shafts but which can’t provide the same level of torque transfer. While both coupling types have their advantages and disadvantages, it’s important to know which coupling to choose in a particular application.


  • What is the difference between flexible coupling and rigid coupling?

  • What are the features of flexible coupling?

  • What are the applications of flexible coupling?


What is the difference between flexible coupling and rigid coupling?

Rigid shaft coupling cannot compensate for the axial displacement and radial displacement between the connecting transmission shafts. The rigid coupling has a simple structure and a low price, which is suitable for two shafts with good concentricity.

Flexible shaft coupling can compensate for the axial displacement and radial displacement between the connecting shafts. The structure of the flexible coupling is relatively complicated and the price is relatively high. It is suitable for the situation where the concentricity of the two shafts is not very good, and is suitable for the situation with torsional vibration to reduce vibration.

The main difference between rigid couplings and flexible couplings is the connection they provide. Rigid coupling provides a rigid connection, that is, two shafts are firmly connected, and the coupling can transmit torque smoothly in the entire system. A flexible coupling can form a flexible connection, and the components may lose some torque through interaction.

  • Alignment Requirements: Flexible couplings can handle slightly misaligned shafts. Rigid couplings are stiff and can’t tolerate any misalignment. This applies to both shafts that are physically misaligned at rest and parts that may cause misalignment during operation due to thermal changes.

  • Backlash: Rigid couplings, especially newer models of aluminum rigid couplings, can significantly reduce backlash to at-zero or near-zero levels. Flexible couplings don’t offer the same protection.

  • Maintenance Requirements: Because rigid couplings are stiff, they do not absorb vibrations, which can lead to early wear on parts that aren’t properly aligned. Operators should routinely check rigid couplings for wear and alignment, and they should also routinely apply lubricant. Flexible couplings can handle vibration and shock without adverse wear.

  • Complexity: Flexible couplings often have more components and are more complex. This can make operation and maintenance more complicated. Rigid couplings are simpler and more straightforward.

  • Applications: Flexible couplings can be used in servos with low or moderate torque levels and the potential for shaft misalignment. This includes applications such as machining tools, semiconductor manufacturing, and packaging equipment. Rigid couplings work best for high-torque requirements, shaft support applications, and push-pull use cases.

  • Cost: Rigid couplings are more affordable than flexible couplings, which tend to have a high cost.


What are the features of flexible coupling?

The flexible coupling is simple in structure, easy to manufacture. Flexible coupling does not require lubrication and does not need to be bonded with metal vulcanization, as well as not moving the half coupling. Flexible coupling is convenient to change the elastic sleeve and has the properties of compensating the relative deviation of the two shafts and the ability of damping.

1.      Flexible coupling is one-piece metal elastomer.

2.      Flexible coupling has zero backlash and can perform synchronous operation.

3.      Flexible coupling has elastic action compensates radial, angular and axial deviations.

4.      Flexible coupling is high torque rigidity and excellent sensitivity.

5.      Characteristic of flexible coupling is that clockwise and counterclockwise rotation are exactly the same.

6.      Flexible coupling is maintenance-free, oil and corrosion resistance.

7.      There are aluminum alloy and stainless-steel materials for selection of flexile coupling.

8.      There are two main fixing methods of flexible coupling that are top wire and clamping.

9.      Flexible coupling is dry coupling without lubrication. The flexible coupling relies on the metal diaphragm to transmit torque and absorb the deformation caused by misalignment. There is no relative movement between the parts, no friction and wear, so it does not need lubrication.

10.   Flexible coupling has large torque transmission capacity with long service life.

11.   After the flexible coupling is loaded, a large additional axial force and additional bending moment will be generated on the shaft and the bearing due to friction and misalignment of the two shafts.


What are the applications of flexible couplings?

The work of the elastic sleeve is compressed and deformed. Although the flexible coupling can compensate the axis displacement and elasticity, the allowable compensation amount for the axis displacement is less and the elasticity is weak because of the thin elastic sleeve, the small volume and the limited elastic deformation. The flexible coupling relies on the locking force of the pin group to generate the friction torque on the contact surface, and compress the rubber elastic sleeve to transmit the torque.

Flexible coupling is suitable for the transmission of small and medium power water pumps with high speed, high rigidity of the installation base, high centering accuracy, low impact load, and low vibration reduction requirements.

One of the high-review couplings, gear coupling is of enormous use in material apparatus, scoops, draglines, air blowers, blowers and fans. The explicit element of this sort of flexible coupling is that it gives a high torque weight proportion. High torque of gear coupling clears a path for little couplings and gives better yield. Gear coupling’s huge bore limit permits littler and less expensive couplings. Gear coupling is exchangeable, in this manner diminishing burden on the rigging network and expanding the center quality.

Typical applications of universal joints include aircraft, electrical appliances, control mechanisms, electronic equipment, instrumentation, medical and optical equipment, ordnance, radios, sewing machines, textile machinery and tool drives. The universal joint can be made of steel or thermoplastic. Under a given size, steel universal joints have the greatest load-bearing capacity. Universal joints with thermoplastic body parts are used in light industrial applications. Its self-lubricating properties, light weight, negligible recoil, corrosion resistance and high-speed running capabilities are significant advantages. Spherical universal joints are used for high-speed operation and transmission of large torque.


Learn more something about flexible couplings can know the differences between rigid coupling and flexible coupling and the applications of flexible couplings. If you want to buy good shaft couplings with reasonable price, FOSHAN HOUZHE TRANSMISSION EQUIPMENT CO., LTD. is your best choice. Whether from quality or price, or delivery time, we can help customers to open up a further and larger market with all types of different flexible couplings.




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