What is a rigid coupling? What coupling corresponds to it? Why are rigid couplings used in low-power pumps

Rigid coupling: A rigid coupling does not have the ability to compensate for relative misalignment between the axes of the two shafts it connects, nor does it possess any shock-absorbing properties； But it has a simple structure and is inexpensive. Rigid couplings can only be used when the load is stable, the rotational speed is steady, and it can be ensured that the relative offset between the axes of the two connected shafts is minimal. What corresponds to it is a flexible coupling. A flexible coupling has the ability to compensate for relative misalignment between the axes of the two shafts it connects, with the maximum degree of compensation varying depending on the model. Flexible couplings with inelastic elements, flexible couplings with non-metallic elastic elements, flexible couplings with metallic elastic elements. Flexible couplings with inelastic elements: they have high load-bearing capacity, but lack shock absorption capabilities; they generate impact noise at high speeds, when the rotation speed is unstable, or during frequent forward and reverse rotations. Suitable for low-speed, heavy-load applications with stable rotation speeds. Flexible couplings with non-metallic elastic elements offer excellent shock absorption performance when the rotation speed is unstable ； However, due to the low strength, short lifespan, limited load-bearing capacity, and susceptibility to high and low temperatures of elastic elements made of non-metals (such as rubber and nylon), they are suitable for applications involving high speeds, light loads, and normal temperatures. Flexible couplings with metal elastic elements, on the other hand, not only offer good shock absorption properties but also have a high load-bearing capacity; they are thus suitable for situations with large variations in speed and load, as well as in high- or low-temperature environments.

A rigid coupling does not have the ability to compensate for relative axial misalignment between the two shafts it connects, nor does it possess shock-absorbing properties； What corresponds to him is a flexible coupling, which has the ability to compensate for relative misalignment between the axes of the two shafts it connects; the maximum amount of this compensation varies depending on the model. Flexible couplings with inelastic elements, flexible couplings with non-metallic elastic elements, and flexible couplings with metallic elastic elements – these all fall under the category of elastic couplings (flexible couplings), but they have a simple structure and are inexpensive. Rigid couplings can only be used when the load is stable, the rotational speed is steady, and it can be ensured that the relative offset between the axes of the two connected shafts is minimal.

Are there pictures of rigid couplings and flexible couplings?

Generally, large compressors and turbines are rigidly connected, and they are not used in many applications.

It seems that gear couplings are commonly used in steam turbines