What is a coupling
Coupling is a mechanical component used to firmly connect the driving shaft and driven shaft in different mechanisms, rotate together, and transmit motion and torque. Sometimes it is also used to connect the shaft with other parts (such as gear, pulley, etc.). It is usually composed of two halves, which are connected with keys or tight fit respectively, fastened at the two shaft ends, and then the two halves are connected in some way. The coupling can also compensate the offset between the two shafts due to inaccurate manufacturing and installation, deformation or thermal expansion during operation (including axial offset, radial offset, angular offset or comprehensive offset); And mitigate impact and vibration absorption.
Most of the commonly used couplings have been standardized or standardized. Generally, it is only necessary to correctly select the type of coupling and determine the model and size of coupling. If necessary, check and calculate the load capacity of vulnerable weak links; When the rotating speed is high, the centrifugal force at the outer edge and the deformation of elastic elements shall be checked for balance verification.
Type of coupling
Couplings can be divided into rigid couplings and flexible couplings.
Rigid coupling does not have the ability of buffering and compensating the relative displacement of two axes, and requires strict alignment of two axes. However, this kind of coupling has the advantages of simple structure, low manufacturing cost, convenient assembly, disassembly and maintenance, which can ensure high alignment of two axes, large transmission torque and wide application. Flange coupling, sleeve coupling and clamping shell coupling are commonly used.
Flexible couplings can be divided into flexible couplings without elastic elements and flexible couplings with elastic elements. The former only has the ability to compensate the relative displacement of the two axes, but can not buffer and reduce vibration. The common ones are slider couplings, gear couplings, universal couplings and chain couplings; The latter type contains elastic elements, which not only have the ability to compensate the relative displacement of the two axes, but also have the functions of cushioning and vibration reduction. However, the transmitted torque is generally less than that of flexible couplings without elastic elements due to the strength limitation of elastic elements. The common ones are elastic sleeve pin couplings, elastic pin couplings, quincunx couplings, tire couplings Serpentine spring coupling and reed coupling, etc.
Performance of coupling
According to different working conditions, the coupling shall have the following properties:
- (1) Mobility. The movability of coupling refers to the ability to compensate the relative displacement of two rotating members. Factors such as manufacturing and installation errors between connected components, temperature changes in operation and load deformation all put forward requirements for portability. The movable performance compensates or relieves the additional load between shafts, bearings, couplings and other parts caused by the relative displacement between rotating members.
- (2) Buffering. For the occasion of frequent load start or working load change, the coupling shall be provided with elastic elements that play the role of buffer and vibration reduction, so as to protect the prime mover and working machine from damage.
- (3) Safe and reliable, with sufficient strength and service life.
- (4) The utility model has the advantages of simple structure, convenient assembly, disassembly and maintenance.
When selecting the coupling type, the following items should be considered.
- ① The magnitude and nature of the required transmission torque, the requirements for cushioning and damping functions, and whether resonance may occur.
- ② The relative displacement of the axes of the two shafts is caused by manufacturing and assembly errors, shaft loading and thermal expansion deformation, and relative motion between components.
- ③ The allowable overall dimensions and installation methods, and the operation space necessary for assembly, adjustment and maintenance. For large couplings, it shall be possible to disassemble and assemble the shaft without axial movement.
- In addition, the working environment, service life, lubrication, sealing and economy shall be considered, and then a suitable coupling type shall be selected with reference to the characteristics of various couplings.
Source: China Coupling Manufacturer – Yaang Pipe Industry Co., Limited (www.steeljrv.com)
(Yaang Pipe Industry is a leading manufacturer and supplier of nickel alloy and stainless steel products, including Super Duplex Stainless Steel Flanges, Stainless Steel Flanges, Stainless Steel Pipe Fittings, Stainless Steel Pipe. Yaang products are widely used in Shipbuilding, Nuclear power, Marine engineering, Petroleum, Chemical, Mining, Sewage treatment, Natural gas and Pressure vessels and other industries.)
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