1. What is Shaft Coupling?
Shaft coupling is a mechanical component used to firmly connect the driving shaft and the driven shaft in different mechanisms to rotate together and transmit motion and torque. Sometimes it is also used to connect the shaft with other parts (such as gears, pulleys, etc.). It is often composed of two halves, which are connected by keys or tight fits, fastened to the two ends of the shaft, and then connected in some way. The coupling can compensate for the offset (including axial offset, radial offset, angular offset or combined offset) between the two shafts due to inaccurate manufacturing and installation, deformation during operation or thermal expansion, as well as mitigate impact and absorb vibration.
2. Shaft coupling can be divided into two major categories:
1. Rigid coupling. It does not have the ability to buffer and compensate for the relative displacement of the two axes, and requires the two axes to be strictly aligned. However, this type of coupling has a simple structure, low manufacturing cost, easy assembly and disassembly, and maintenance. Rigid coupling can ensure that the two shafts have a high degree of alignment, transmit a large torque, and is widely used. Commonly used ones include flange couplings, sleeve couplings and clamp couplings.
2. Flexible couplings. It can be divided into flexible couplings without elastic elements and flexible couplings with elastic elements. The former only has the ability to compensate for the relative displacement of the two axes, but cannot buffer and reduce vibration. Common ones include slider couplings, gear couplings, universal couplings and chain couplings. The latter contains elastic elements. In addition to the ability to compensate for the relative displacement of the two axes, it also has buffering and vibration reduction effects. However, the transmitted torque is generally not as good as the flexible coupling without elastic elements due to the limitation of the strength of the elastic elements. Common ones include elastic sleeve pin couplings, elastic pin couplings, plum blossom couplings, tire couplings, serpentine spring couplings and leaf couplings.
3. According to different working conditions, the coupling needs to have the following properties:
1. Movability. The mobility of the coupling refers to the ability to compensate for the relative displacement of the two rotating components. Factors such as manufacturing and installation errors between connected components, temperature changes during operation, and load deformation all put forward requirements for portability. Portability compensates or alleviates the additional loads between shafts, bearings, couplings and other parts caused by the relative displacement between rotating components.
2. Buffering. For occasions with frequent load starting or changes in working load, the coupling must have elastic elements that play a buffering and vibration reduction role to protect the prime mover and working machine from less or no damage.
3. Safe, reliable, with sufficient strength and service life.
4. Simple structure, easy to assemble, disassemble and maintain.
